Wikipedia:Reference desk/Computing

Reference Desk

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July 20

First! --Abnerian 11:38, 20 July 2006 (UTC)

Excellent. This reference desk should provide useful henceforth. --Proficient 11:57, 20 July 2006 (UTC)

Shouldn't there be a "how to ask a question" and "how to answer" section first? schyler 12:19, 20 July 2006 (UTC)

There is now ;-) -- AJR | Talk 13:09, 20 July 2006 (UTC)

Should we make a section for commonly asked questions (What is the best programing language?)Jon513 18:03, 20 July 2006 (UTC)

A little premature on the first day? We don't know what questions are commonly asked yet. Theresa Knott | Taste the Korn 18:16, 20 July 2006 (UTC)

So far the most "common" questions seem to be coming from Ubuntu users. But as time passes, we'll probably find some more Windows users. --Optichan 20:41, 20 July 2006 (UTC)

WLAN USB-Stick and Linux

Which USB-WLAN adapter works with Linux? I dont't want to have to recompile the kernel, edit too many configfiles, and things like That. Would it be better then, to use a PIC card? Thank You! --192.94.73.30 12:59, 20 July 2006 (UTC)

If you are willing to install ndiswrapper, you can use just about any Windows driver and, therefore, just about any USB:WLAN adapter. That's how I got mine working. --Kainaw ^(talk) 16:45, 20 July 2006 (UTC)

I'll try that. Thank You! --192.94.73.30 13:47, 21 July 2006 (UTC)

Sound stopped working in Ubuntu

All of a sudden, for no reason that i can think of some sounds are no longer being produced. For example movies on My Tube now play without any sound. Tuxpaint doesn't produce sounds any more. However my alarm clock still plays ACDC at 6.00 am just fine and Gnometris bleeps away merrily. Any ideas? Theresa Knott | Taste the Korn 15:19, 20 July 2006 (UTC)

Does your soundcard do hardware mixing? That is, if you kill esound, can two programs still play audio at the same time? —Keenan Pepper 15:58, 20 July 2006 (UTC)

OK I better explain - please treat me as a complete and utter idiot. Spell everything out as you would a child (my knowledge of linux is very limited) I don't know what hardwear mixing is :-( Theresa Knott | Taste the Korn 16:03, 20 July 2006 (UTC)

Okay, the basic problem is that you want different programs to play sounds and have them come out the speakers at the same time. There are two solutions. The best one is to have a sound card that mixes the sounds together in hardware, so each program can act as though it has the sound card all to itself, and the software doesn't have to do anything. Only expensive sound cards do that, though. The other solution is to have a program running all the time (in your case, the Enlightened Sound Daemon, aka "esound" or "esd") that mixes the sounds together in software. Esound is the only program that directly accesses the sound card, and all the other programs have to go through esound.

Do you know what model of sound card you have? —Keenan Pepper 17:35, 20 July 2006 (UTC)

I'm not 100% certain as I can't find the documention but I'm pretty sure it's onboard sound. The computer was a cheap one. Theresa Knott | Taste the Korn 18:13, 20 July 2006 (UTC)

I remember reading something on the Ubuntu forums or wiki about forcing all your programs to use esound. I'll try to find it. --Optichan 20:27, 20 July 2006 (UTC)

Okay, then it probably doesn't do hardware mixing, so you'll have to use esound. I just found out what a big hairy mess flash+esound is (mostly Macromedia's fault), but you can try these instructions. Open up a terminal (I think it's in "accessories"), type sudo ln -s /usr/lib/libesd.so.0 /usr/lib/libesd.so.1, and hit enter. You'll have to enter your password. Do the same for the other two lines beginning with "sudo". Generally you should be careful with "sudo" commands, but these three are quite safe. —Keenan Pepper 20:30, 20 July 2006 (UTC)

Ctrl+Shift+Enter to send message in Thunderbird

I was typing a message in Thunderbird 1.5.0.4 on Ubuntu Dapper 6.06. I went to hit Ctrl+Enter to send the e-mail, but hit Ctrl+Shift+Enter by accident.

Where did my e-mail go??

--Silvaran 17:46, 20 July 2006 (UTC)

Got it! It went to Local Folders->Unsent. I just do Edit As New, and then Send. Hope this helps somebody else :). --Silvaran 17:48, 20 July 2006 (UTC)

There is a list of keyboard shortcuts here, although it only said that ctrl+shift+enter means "send later", it didn't actually say where it went. --LarryMac 17:55, 20 July 2006 (UTC)

Yeah, the same kind of thing happens with trash and "sent items". Different mail programs seem to have different places to put deleted messages and copies of sent messages (though some, like Thunderbird, are configurable). Part of my confusion stemmed from the fact that these "send later" messages were saved in the "Local Folders" section rather than the currently active account (in my case, an IMAP account). Thanks for the link BTW.--Silvaran 03:25, 23 July 2006 (UTC)

What is a parm file?

I would like someoone to explain to me what a parm file is.

It's a badly abbreviated name for a parameter file. Unfortunately, it's very hard to be more specific than that, as many different programs and systems have parameter files, and there is no standard. Generally a program will read the contents of a parameter file when it first starts up, using the information in the file to set certain values that will be used as the program runs. However a program might read the contents of the parm file at any time. The Windows Registry could be considered a giant parm file -- it contains hundreds if not thousands of pieces of that tell Windows things like what image to use as the desktop background, what color to use as a windows border, and which font to use to label icons. A parm file for my super-duper weather reporting program might have entries to tell it whether to use degrees Fahrenheit or degrees Celsius, and how fast a wind gust should be to trigger an alarm. --LarryMac 19:51, 20 July 2006 (UTC)

The Parameter article gives examples and types. A lot of the software that I use, requires that the parameters be in a particular sequence, and be of a certain length, because the software that processes the parm file might not define things the same way as the one that feeds it the info. User:AlMac|^(talk) 20:50, 20 July 2006 (UTC)

Listboxes in Visual Basic 6

I'm using a timer event to update a listbox every second. Each time it is updated, it automatically scrolls to the top. However, the most recent entries are at the bottom and I'm wondering if I can stop this scrolling action, or use a command to make it scroll down. Robmods 21:43, 20 July 2006 (UTC)

Do the items have to be added to the bottom of the list? You could just add them to the top. Alternately, you could set the focus to the last item in the list on each update, I believe. 128.197.81.223 23:07, 20 July 2006 (UTC)

You can make the box scroll to the bottom like this:

' add a random number to the list
ListBox1.AddItem Int(10 * Rnd) + 1
' set the selected item to be the final one
' the list starts at 0, so the final item is the total minus one
ListBox1.ListIndex = ListBox1.ListCount - 1

Enjoy! Icey 12:55, 21 July 2006 (UTC)

Thanks - I've managed to fix my program by changing focus. Robmods 17:50, 21 July 2006 (UTC)

July 21

Microprocessor

How does the microprocessor 8089C-51ED-2 work and where can I find the information related to it on the net? --K.C.Priyanka 02:59, 21 July 2006 (UTC)

I repaired the question so easier for people to read it User:AlMac|^(talk) 05:01, 21 July 2006 (UTC)

I am not an expert on this aspect of computer technology, but I did skim over the Wikpedia article on microprocessor and saw numbers right around the 8089 but not dead on. Looks to me like it might be made by Intel so perhaps their web site http://www.intel.com/ might be a place to check. User:AlMac|^(talk) 05:09, 21 July 2006 (UTC)

You can find a lot of information on the Internet by using search engines, such as this way http://www.google.com/search?hl=en&lr=&q=8089C&btnG=Search User:AlMac|^(talk) 05:04, 21 July 2006 (UTC)

It appears to have been an Intel chip c. 1982 that was used mainly as an Input/Output co-processor. The Intel website doesn't seem to cover it though. Robmods 12:57, 21 July 2006 (UTC)

System requirements

I could swear that once someone told me how to see information on memory, graphics cards etc. in a way that was useful to compare to system requirements lists on computer games. It's not under Help and Support or My Computer, as far as I can tell. Help plz? Vitriol 17:25, 21 July 2006 (UTC)

You mean to see the stats of your own computer? On Windows XP: to see your processor and RAM stats, right click on My Computer and select "properties", and it will be there. For other more detailed stuff, including Graphics cards, sound cards, disk drives, etc, right click on My Computer, select "Manage", and then from the list on the left column of the screen that pops up, select "Device manager". If you need more help than that just ask. —Mets501 (talk) 17:29, 21 July 2006 (UTC)

I'm sure it was easier than that. Vitriol 17:38, 21 July 2006 (UTC)

If you have directx installed, you can go start->run->dxdiag and get a lot of information, though perhaps not what you're looking for. Digfarenough 19:13, 21 July 2006 (UTC)

Wow, that's cool! I didn't know about that! —Mets501 (talk) 19:18, 21 July 2006 (UTC)

Since you don't specify what operating system you are using, you probably don't realize that the question exists, which means you are using some version of Microsoft Windows. In that case, some freely downloadable utilities are SiSoftware's Sandra, Lavalys EVEREST (though support has been discontinued), CPUID's PC Wizard 2006, and Belarc Advisor (which generates a summary). --KSmrq^T 20:27, 21 July 2006 (UTC)

It's too late, Digfarenough got it. I remember now. :D Vitriol 20:56, 21 July 2006 (UTC)

Software utilities such as Everest or the abovementioned software are sometimes easier to use and contain more information. CPU-Z is also useful. --Proficient 23:10, 21 July 2006 (UTC)

Code library conversion

I've got a code library (a .lib file) compiled with Microsoft Visual C++. How do I use it with the Windows version of GCC? Do I need a converter? --67.185.172.158 17:32, 21 July 2006 (UTC)

This may be what you're after. EVOCATIVEINTRIGUE TALKTOME | EMAILME | IMPROVEME 17:34, 21 July 2006 (UTC)

Python: Setting a "global" variable with a function.

Any variable used within a function is strictly local: as I understand it, it cannot be used / doesn't exist in the rest of the program. This is proving to make a lot of code repetative in the programs I'm writing, so a method to get around this is what I'm looking for.

I've tried something like this:

  variable = myFunction()

This puts the result of myFunction as the value of the variable. However, this method can only be used for one variable. I was thinking of perhaps returning the values of the function as a concatenated string.. i.e. if myFunction had five values (01, 02, 03, 04 and 05) I wanted to be variables, it returns the string:

  0102030405

I would then set something like:

  variable = myFunction()
  a = variable[0:2]
  b = variable[2:4]
  c = variable[4:6]
  d = variable[6:8]
  e = variable[8:10]

This seems to be a very clumsy solution though; perhaps there is a more elegant solution?

I'm very new at programming, and am following an online guide to learning the language from scratch. I've tried looking in the index of the guide I'm reading and couldn't find anything, and I also tried searching Google but with no luck.. Any help would be much appreciated.

P.S. It just occurred to me that the variables above (a,b,c,d,e) are strings, I know I'd have to convert them to integers to be able to use them, so there's no need to correct me on that.

If myfunction returns a 5-tuple (constructed like (1, 2, 3, 4, 5)), you can unpack it like

a, b, c, d, e = myfunction()

instead of that ugly, overflow-prone string encoding method. When multiple values are required to be returned, a tuple is your best bet. --Sam Pointon 20:20, 21 July 2006 (UTC)

I've never encountered the word tuple before. So thanks for that, now I have something to search for so I probably won't have a problem finding the rest out for myself. Thanks again!

In Python, you can access a global variable inside a function by declaring the variable to be global, using the keyword "global". Example:

   def f():
       global v
       v = 1
   
   v = 0
   f()

After executing the above code, global variable v will be set to 1.--68.238.246.143 02:38, 22 July 2006 (UTC)

I'd just like to note that the above, global-modify code, is bad style. global statements should be used very sparingly (ideally, none at all). If a function needs mutable state, use a class:

class Foo(object):
    def __init__(self):
         self.v = 0

    def f(self):
         self.v = 1

foo = Foo()
f.f()

After that block of code, foo.v is set to 1. --Sam Pointon 10:29, 22 July 2006 (UTC)

eMule

My computer crashed a few minutes ago. This caused me to lose connection to the eMule server I was connected to and now I get connected to another one which doesn't have any of the files I was downloading. How do I see which server I need to connect to? There's too many to choose from. Is there some sort of server connection log? = Mgm|^(talk) 22:01, 21 July 2006 (UTC)

• Follow-up: The new server says I have a LowID. How do I get a HighID again? Did I ever have one. Speeds seem to be down in general. - Mgm|^(talk) 22:40, 21 July 2006 (UTC)

Try reestablishing the connection again. Check to see that you have your [ports forwarded|port forwaring]. Make sure that your firewall is allowing you to use eMule. Did you do any upgrades to any programs? Try to turn off your modem and try again. --Proficient 23:11, 21 July 2006 (UTC)

• Somehow I got it working again. Thanks for trying. My firewall (if I have one) allowed me to use eMule so far, so I see no reason for it to not work now. I had the crash when I was playing a video file, no upgrades, and I don't use a modem -- that's too slow a connection. - Mgm|^(talk) 08:19, 22 July 2006 (UTC)

'turn off your modem and try again'??? I mean come on! Anyway, edonkey servers are linked together, it does not matter which you connect to with respect to file availability. It does, however, matter that you get a High ID in order to get files from certain sources (namely people with LowIDs). This is where proper port configuration on your firewall is important. --Jmeden2000 15:24, 24 July 2006 (UTC)

Very noisy computer

I want to quieten my very noisy computer. It has two fans - one on the CPU, another on the box.

I think the CPU fan will be impractical to replace as they are attched in a special way to the CPU.

Can anyone tell me what proportion of the total noise do the two fans usually make? In other words, is it worth just replacing the box fan. Will this make any difference?

I would be grateful if anyone could also tell me a) how to identify the exact fan I need, and b) where to buy a quiet fan, preferably by mail-order in the UK?

Thanks. --62.253.52.139 22:35, 21 July 2006 (UTC)

You can replace both fans. I am going to assume you don't know what a CPU looks like - please don't be offended if you do. The CPU is a very thin little chip on the motherboard. It has a large heat sink mounted to the back of it. It clips around the chip and has a lot of (usually white) goop to help transfer heat from the chip to the heat sink. The fan is attached to the heat sink, not the chip. So, you will need to replace the whole heat sink - there are some very quiet ones and some that have no fan at all. As for the case fan, you can get quiet ones too. Check your power supply, that usually has the loudest fan. Then, look at your BIOS. You may have the option to throttle the fan with the CPU's core temperature. That makes a huge difference because the fans run slower when it is cool and then get loud only when it is hot. --Kainaw ^(talk) 00:12, 22 July 2006 (UTC)

As you said yourself, replacing the CPU fan means messing with the 'goop' attached to the CPU - I don't think I want to do this. I only saw this fan and another one at the back of the case when I had it open some time ago - is there another one also?

What you said about the fan throtteling to the CPU temperature is interesting. However I doubt my cheap and old computer can do this - I've explored the various settings on my computer over the years, and I've never come across it. But when I've tried to use free software to measure the CPU temperature, it either gives no reading at all, or it gives a 'meltdown' temperature. My computer has been working OK for months or years since then, so I am sure this is a mistake.

I would be very grateful for any help in identifying the particular fan I need. Thanks again.

There is no such thing as a particular fan. There should be at least 3 fans in any modern computer: One inside the power supply, one inside the case, and one on the CPU. As for the goop on the CPU, new heat sinks come with a tube of goop to replace it. As for the fan in the case and power supply, they are most likely standard 3-inch fans. Those are sold all over - you can go to Radio Shack if you can't find a computer store. There isn't a lot of technology in the basic fan world. The difference is the bearings that hold the fan in place. The quieter the bearings, the quieter the fan. Also, make sure there isn't anything in the fan - like cables, old post-it notes, dead animals... You wouldn't believe what I've pulled out of old computers. --Kainaw ^(talk) 21:31, 22 July 2006 (UTC)

You might be interested in Silent PC Review; they have lots of info, though they border on the obsessive. For your purposes, it would be helpful to know the dimensions of your fans, and what era your computer hails from. - mako 08:14, 23 July 2006 (UTC)

Thank you for the link to the Silent PC Review, I have been reading their fax. It mentions and evaluates various brands of fan, and gives a UK on-line supplier which sells fans, both good and bad.

I do not know what the size of case fan is without opening the case and measuring it. I have a etower 566cd, from about 2001. Although the computer I saw in the shop was silent, my computer has been very noisy from day one. Thanks.

Most modern motherboards have temperature sensors that make fans run faster as temperature increases. Therefore, your PC might be running a little hot. Probably the most common cause of this is dust building up inside. Go and buy a can or two of compressed air, open up your PC's case and blast it all out. Make sure to get it all off the heatsinks and fan blades too. Use a bit of masking tape or something to stop the fans turning, so you don't damage the motors (something I've heard can happen). I wouldn't recommend blowing it all out yourself, as you end up tired, not much dust shifted and a motherboard doused in saliva. DO NOT take a vacuum cleaner near the inside of your PC, as the static electricity from it can damage chips, although you might want one on hand to deal with the inevitable cloud of dust. I've seen my processer temperature drop by 10C after a good cleaning, and by extension, the fans quieting down. CaptainVindaloo ^{t c e} 17:50, 23 July 2006 (UTC)

I did try to buy some compressed air once. In the back-street computer shop I went into I was offered a tin can of something that looked like it was a spray for cleaning keyboards or the outside of cases. It did not mention "compressed air" on itself anywhere. It had a lot of liquid in it, and when I queried this the shop assistant said that that was liquified air! (What a moron!). I did not buy it. So is "compressed air" really compressed air, or is it just some sort of volatile liquid/gas? Thanks.

Compressed air is simply normal air stored under high pressure, which means it will blast out when you open the can. Robmods 21:10, 26 July 2006 (UTC)

I've heard of a new technology for computer cooling that is completely silent, and it gathers no dust. It works through a liquid-cooling system that surrounds the inside parts of the computer that normally get hot. It pumps cold water through plastic bags inside the computer.--epf 21:55, 26 July 2006 (UTC)

One possible source for "fan noise" is a ribbon cable touching the moving fan blades. Remove the outer case from the computer and boot it, to determine the source of the sound. If it is a ribbon cable, just secure it so it doesn't hang into the fan any more. A twist-tie might do the trick. StuRat 00:16, 27 July 2006 (UTC)

Problems with Remote Desktop Connection through my Router

This problem seems ridiculously easy, but I can't figure it out. I have a Linksys Wireless-G broadband router (WRT54G Version 4) directly connected to my computer (the other two family computers connect to the internet wirelessly while this one is hardwired). I can't seem to connect to my computer with Windows XP's Remote Desktop Connection from other computers; it won't resolve my IP address. Any suggestions? Thanks! --Samesong 23:08, 21 July 2006 (UTC)--Samesong 23:08, 21 July 2006 (UTC)

Did you enable incoming remote desktop connections on your computer? --Kainaw ^(talk) 00:13, 22 July 2006 (UTC)

I found this: http://www.microsoft.com/windowsxp/using/networking/expert/northrup_03may16.mspx

This works perfectly :D

July 22

wouldnt quite call it computer SCIENCE, but...

i just got a new computer. id put avg on my old one because someone had suggested it, and i didnt get any viruses or anything. the new computer comes with a trial version, 6 months, i believe, of mcafee. it's bugging the hell out of me, (constant security pop-ups im having trouble turning off, prohibitively large cpu usage at computer startup, causing a long, long, startup) and im considering deleting it before the trial expires. is this a bad idea if i have avg? does avg work fine? should i renew my mcafee or can i just delete it and be perfectly safe. thanks sasha

• Hey, Sasha. Just remove it through Add/Remove programs in the Control Panel. Won't do any harm. Then just install AVG, or something else if you want, although AVG is very good in my opinion. Hope I was of some help. Stewart 14:42, 22 July 2006 (UTC)
• Yes. AVG is popular and effective. --Proficient 14:54, 24 July 2006 (UTC)
• I'd agree that AVG is excellent. I also use ZoneAlarm which allows the user to allow or block any programs that try to access your computer, or any programs that try to access the internet. --Tadhg 22:53, 26 July 2006 (GMT)

Thanks

how to control the keyboard using java script

pls tell me how to control teh key board using java script

What exactly do you mean by "control the keyboard"? What do you want to do with it? The keyboard is just an input device; if you want to simulate the usage of an input device, there are ways to do that within the constraints of the Javascript DOM, but you can't do it outside of that. --Fastfission 14:57, 22 July 2006 (UTC)

Use AutoHotKeys (freeware) to control the keyboard with macros, easily. --Proficient 14:56, 24 July 2006 (UTC)

GIMP: I just go this program and...

Moved here from Talk:GIMP

...well I need to learn how to do something. It says I have not installed the help program so if anyone can tell me how to do that, it would probably clear it up for me. Anyway, my question is how do I get a transparent background. --WillMak050389 20:53, 21 July 2006 (UTC)

Either by selecting what you want to keep, making a new layer (Layer -> New -> Transparent) and pasting it to the new layer, or by cutting what you want to lose from the existing layer. You may have to delete a white background layer. All that happens in the layers dialogue, one of the windows that opens automatically at startup. As for installing the help, you'll have to first tell us what platform you're working on. - Samsara (talk • contribs) 22:10, 21 July 2006 (UTC)

I'm working from Windows XP is that what info you wanted? Oh and I realized I probably should have put this on the Media reference desk and not this talk page. Sorry for that. --WillMak050389 01:47, 22 July 2006 (UTC)

I strongly suggest searching google for "Beginner's Lessons for Gimp". It is almost as hard as Photoshop for a beginner to learn. But, once you get the idea of layers and selections, you will be able to quickly pick up all kinds of tricks. I made the mistake of trying to jump from MS Paint to Gimp with just the Gimp help manual. You do not want to try that. --Kainaw ^(talk) 14:14, 22 July 2006 (UTC)

I found a good beginners help course here. Thanks for the tip, Kainaw! --WillMak050389 00:28, 23 July 2006 (UTC)

doc2odt

is there some command line tool that would allow conversion from Microsoft Word format to .odt? Along the lines of $doc2odt file.doc > file.odt? Does OpenOffice have some sort of script language (analogous to Script-Fu for the GIMP)? dab (ᛏ) 16:47, 22 July 2006 (UTC)

KOffice has kconverter with allows you to do "kconverter file.doc file.odt" to convert types. There is a generic program called "convert" also. It will attempt to convert from any format to any other format. Mine is configured to all popular graphics and music formats. I've never tried it with doc/odt because I normally just open the doc in OpenOffice and click Save As to save it as an odt file. --Kainaw ^(talk) 20:04, 22 July 2006 (UTC)

Abiword has a pretty good converter (use: $ abiword --to=file.odt file.doc). I'm sure OOo does as well. Googling "openoffice automate" brings up a few likely pages. EdC 02:40, 24 July 2006 (UTC)

Cyberspace

(new fangled computing desk, eh?) After reading Neuromancer, I'm interested to see if anyone's ever made a 3D representation of the internet (i.e. Cyberspace) which actually works, in that you can go from site to site, sites are represented geographically, etc. It might be a little complicated but I'd be surprised if no one's actually tried. Know ye of any software like that? Sum0 18:16, 22 July 2006 (UTC)

the problem here is the metric. Representations of the internet I've seen usually take address space as their basis; this is contrary to the idea of cyberspace as I understand it (think distributed peer-to-peer etc.), physical (or ICANN) address space does not need a relation to the logical topology of data. But unless I know exactly what I mean by "logical topology of data", I cannot build a model of the internet, 3D or otherwise. All you get is a boring diagram of how the hardware is wired. 62.202.70.34 19:55, 22 July 2006 (UTC)

See VRML for the first version of 3D internet and X3D for the second version. Neither caught on. In my opinion it is because it is too hard to develop your own 3D homespace, so there's no added benefit to slowly sliding around a large empty void with random flat webpages. --Kainaw ^(talk) 19:59, 22 July 2006 (UTC)

It's also generally harder to manipulate information in a fake-3D world than it is in a series of flat webpages (which can be also easily "stacked" on top of each other and moved around in multiple windows and tabs). I don't see any great advantage to adding a Z dimension, which would just take up extra time to get in between X and Y, if that makes any sense. Fun for games and sometimes models, but not useful for general internet use. --Fastfission 14:40, 23 July 2006 (UTC)

Can you suggest an software to seperate video from sound?

I have this video, but I just need the audio part of it,is there any way to seperate it? Ziyi_cai841117

Sure, there are plenty of applications that would do just that. If the source is DVD, DVD Shrink would work. Probably wouldn't work with video files unless they were VOB files. Check out Afterdawn.com, and you're bound to find something. Hope that helps. Debigulator 01:22, 23 July 2006 (UTC)

VirtualDub or VirtualDubMod or avidemux will probably do the trick. - mako 08:23, 23 July 2006 (UTC)

If you're using linux, mplayer video.whatever -dumpaudio -dumpfile audio.whatever will supposedly extract the audio track from any media file. (Though it seems to die with my current build on Ubuntu Dapper. Time to file another bug report...) grendel|khan 14:15, 23 July 2006 (UTC)

Thank you!- Ziyi_cai841117

Good old Windows Movie Maker should work, I think.--epf 21:57, 26 July 2006 (UTC)

Grabbing printable versions of some Wikipedia articles

Hi all, I have been playing with migration schemes for the articles listed in User:Hillman/Archive. I have already succesfully used to a simple shell script to download the raw wiki code using the utility wget

#!/bin/sh
# grab raw wiki code for given version of given Wikipedia article
# syntax getrawver ARTICLENAME version
# This saves raw wikicode in file ARTICLENAME in this directory
wget -O $1 "http://en.wikipedia.org/w/index.php?title=$1&oldid=$2&action=raw"

I used another simple shell script to massage User:Hillman/Archive into a file called "runme" which looks like

getrawver Constraint_counting 39565830
getrawver Tidal_tensor 28781955
...

Then I ran another small script

#!/bin/sh
# Syntax
#       getmyn LIST
# Here LIST is ASCII file whose lines each have a unix command with appropriate arguments
# We run each command and quit
exec < $1
while read line
do
        $line
done

I am sure this could be further improved, but it worked fine for the small number of articles I wanted to grab, and that task is now done.

I am now working on the hard part, a wiki2tex utility and hope to semiautomagically latexify these for use on my local machine. For debugging, it would be useful to also have printed versions of the "printable versions" of these articles. To see what I want, go to Constraint counting, look in the history file for the last version edited by User:Hillman, go to that, click on "printable version" and then (if you are using Firefox) click on File -> Save Page As and use the "Web page, complete" option. When you navigate on your local machine to the directory where you saved the file, you should see index.php.html plus a directory called index.php_files which contains all the .png files containing images of in-line mathematical equations from the original, any figures, etc.

The point is that you should now be able to view and/or print this locally even if you are not connected to the internet. (Links to other Wikipedia articles may be represented by internal links which might be broken, but I am not worrying about that right now since I only want to print the article.) If you didn't choose "Web page, complete", you'd just get one html file with external links to all the various .png images.

It must be possible to write a simple script getprintablearts using something like

wget -nc -S -P./Wikipedia/HTML/$1 "http://en.wikipedia.org/w/index.php?title=$1&oldid=$2&printable=yes"

Unfortunately, this seems to save the nonprintable web page with links to the original URLs with the .png files. I tried adding the -r option but this also doesn't seem to give the desired result. Any suggestions? ---CH 22:02, 22 July 2006 (UTC)

The "printable" and normal versions of the pages are exactly the same; the only difference is that the "printable" version always use the print stylesheet, while the normal version only uses the print stylesheet when printing (try it: do a print preview of any Wikipedia page, and notice it is identical¹ to what you would get with the printable version). The "printable version" link was added to reduce confusion from people who are used to seeing it on other sites; it's in fact not needed at all.

What you need is -p (to download the images, stylesheets and scripts used by the page) and -k (to rewrite the downloaded page to point to the objects downloaded by -p). You probably will also need a combination of -H and -D to allow it to get the images from the image server, and possibly other switches; see the wget manual for more information. I would also recomment the use of -w (to add a delay) and a explicit delay between each download, to avoid hammering the Wikimedia servers. --cesarb 16:59, 23 July 2006 (UTC)

¹ Well, almost identical; there are a few style rules that, even in the "printable" version, are only enabled when actually printing. --cesarb 17:04, 23 July 2006 (UTC)

Hi, CesarB, thanks, but if you mean that I should run

wget -nc -p -k "http://en.wikipedia.org/w/index.php?title=$1&oldid=$2&printable=yes"

or

wget -nc -p -k "http://en.wikipedia.org/w/index.php?title=$1&oldid=$2

this don't behave anything like what you said. ---CH 23:36, 23 July 2006 (UTC)

What I meant is wget -nc -p -k -H -D wikipedia.org,wikimedia.org "http://en.wikipedia.org/w/index.php?title=$1&oldid=$2". Unfortunately, at least the version of wget I have here does not understand the @import used to load the CSS files; you will have to edit each downloaded file yourself to point it to the correct places, and download the CSS files by hand. --cesarb 02:23, 24 July 2006 (UTC)

Hi again, thanks, I think you are right, the problem is that wget doesn't play nicely with CSS. Regarding the claim that downloading the "nonprintable" html version and choosing "Print Preview" in my browser being equivalent to downloading printable version, at least on my system these are definitely not equivalent at all! Oh well, fortunately I don't really have so very many files to download so I'll do it "by hand" after all. ---CH 02:43, 24 July 2006 (UTC)

Python

In python, you can make a string "raw" by putting an r in front of it. e.g. r"this string is now raw"

If I have a variable, x, which is a string, how do I make it raw?

Strings aren't inherently raw or non-raw. All the r does is alter the escaping. In a normal string, the backslash has all kinds of magical connotations for the parser, but (nearly) all of these vanish for raw strings. Eg:

>>> "foo\x61bar"
"fooabar"
>>> r"foo\x61bar"
"foo\\x61bar" #note the escaping here.

What I think you might want is repr, which escapes all the backslashes and weird characters in a string, but I'm not too sure. If you'd explain your motivation a little, a better/more fitting solution could be offered. --Sam Pointon 23:07, 22 July 2006 (UTC)

I'm asking the user for the path of the file that is to be opened and I don't want him to have to type an r in front of his response (it's bad enough to have to type in the quotes) like this: r"<path>"

here's my code:

loc = str(input("enter file path:"))

f = file(loc, "r")

of course, this won't work because all the icky "\"s fuddle things up. Using:

f = file(repr(loc), "r") seems to double up the "\"s for some reason..

f = file(repr(loc), "r")

IOError: [Errno 2] No such file or directory: "'C:\\\\test\\\\test.txt'"

but a simple f = file(r"C:\test\test.txt") does work.

Perhaps you should use raw_input, then you don't need to use anything special when typing your pathname. E.g.

loc = raw_input("Filename: ")

f = file(loc, "r")

"input(prompt)" is just a shortcut for "eval(raw_input(prompt))", and you're trying to get around the "eval" bit...-gadfium 05:45, 23 July 2006 (UTC)

Online RSS Aggregator w/o signup

Does such a thing exist? Thanks! Debigulator 01:18, 23 July 2006 (UTC)

Without a login how would the site keep track of which rss feed you want? Jon513 01:06, 23 July 2006 (UTC)

If one would choose a username and attach feeds to that. I suppose it would be 'wiki'ish in principle, only if so and so found the username. Or even a simple signup would be acceptable I suppose. Debigulator 01:18, 23 July 2006 (UTC)

Google Personalized Homepage Jon513 01:38, 23 July 2006 (UTC)

I realised last night all that I really wanted was a place to sign into, and then have it accessible at www.whatever.com/username, so I don't have to sign in to view it. I have personalised a Google homepage, although I don't use my gmail too often, so don't bother signing in. Anyway, I have done some feed to html stuff and whatnot on my own site, although that doesn't have a great layout (need to work on my css). Enough rambling. Thanks, as I have figured out more along what I am looking for! Debigulator 02:09, 24 July 2006 (UTC)

python again

why is it such an affront to python's worldview to assign a string with a "\" at the end of it? how does this language handle filenames and directories?

Python 2.4.3 (#2, Apr 27 2006, 14:43:58)
[GCC 4.0.3 (Ubuntu 4.0.3-1ubuntu5)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> s = 'This is a string that ends with a \\'
>>> print s
This is a string that ends with a \
>>>

What's the problem? —Keenan Pepper 03:39, 23 July 2006 (UTC)

I think he doesn't know what an escape sequence is? I don't know Python, but I assume that you use \ in order to indicate things like in-line quotation marks (i.e. s = "This is a \"string\"") and newlines and things like that. If that's the case, then you need to use two of them to indicate that you really mean a slash and not an escape character. (Again, I don't know Python but it is the same thing in PHP). --Fastfission 14:34, 23 July 2006 (UTC)

By the way: you do not have to use \ as the directory separator, even in Windows. Windows allows the use of both / and \. --cesarb 16:42, 23 July 2006 (UTC)

What is difference of 700MB & GB?

I am trying to put the file"My Documents" on Disc's and what I have now are 700 MB 80 minute 32X and 52X, and I got a message saying I needed to remove 4.12GB before I could use the Disc I have. I have NO CLUE as what that means. I am Computer Illiterate and would appreciate any help someone would be kind enough to give me. What kind of discs do I need to get to accomplish my mission? Thanking you in advance.--Gwynnthebaby 14:54, 23 July 2006 (UTC)

That probably means you have too much stuff in My Documents and the disk can't hold that much. --Yanwen 15:55, 23 July 2006 (UTC)

You could burn a bit at a time. 1000MB is 1GB. So I assume the message means that what is in your My D. is 4.12GB + 700MB, which comes in at 4.82GB. That's several times bigger than what a CD can hold. You're better off burning parts of it onto about 6 cd's, cutting some out, or zipping it (makes it smaller. Have you got a DVD burner? --martianlostinspace 16:22, 23 July 2006 (UTC)

Unless you have a few movies (which should take up one or two CDs each) or a lot of songs (which could take up a CD or two depending on how many you have), most of you most important documents (text ect) are pretty small. Go through the My documents folder and see what you really need to keep it should be well under 700 MB (certainly not 4.82 GB). Jon513 20:20, 23 July 2006 (UTC)

Just to clarify 1Gb = 1024Mb - Spider

It depends on whether you're refering to a decimal gigabyte or a binary gigabyte. A decimal Gigabyte is 1000 MB, but a binary gigabyte is 2³⁰ bytes, which is 1024 MB. Harryboyles 02:35, 26 July 2006 (UTC)

So that's how those hard drive manufactures rip us off. Jon513 03:06, 26 July 2006 (UTC)

Rip us off? Impossible! ;) Optichan 19:25, 27 July 2006 (UTC)

Startup

whenever i turn my pc on a picture of the desktop flashes before the loading screen comes up. how do i stop this from happening?

thanks --86.130.255.231 18:35, 23 July 2006 (UTC)

What operating system?Jon513 20:16, 23 July 2006 (UTC)

I bet it is Windows 98. The default user (the first one added to the system) has a picture as his/her background. The default user's background loads and then runs the login program that shows the login screen. Kind of a dumb hack, but it functions. So, the default user needs to remove the picture from his/her background. When I had a lab full of Win98 machines, the first (default) user was an admin account and it had a black background so that flash of the background wasn't noticed. --Kainaw ^(talk) 21:51, 23 July 2006 (UTC)

No it's Windows XP and i've checked and it's only the old desktop that flashes --86.130.255.231 09:06, 24 July 2006 (UTC)

In Windows XP, to change the background colour of the default user, click Start then Run. In the box that appears type regedit. This will open the Registry Editor. After backing up the registry (click on File menu, Export. Select the All option under Export Range. Name it something like registrybackup, specify a location and click Save), expand HKEY_USERS, then .DEFAULT, Control Panel and click on Colours. In the right pane, right click on the Background key and go Modify. In the resulting Edit String dialog box, Leave the Name field as is. The value field in this instance is the decimal RGB number for the colour expressed between 0 and 255. For example with the value "0 78 152", 0 represents the intensity of red, 78, green and 152, blue. 0 is no colour and 255 is full colour, giving 0 0 0 as black and 255 255 255 as white.

In Paint you can get the RGB value of the colour you want by going to the Colours menu and selecting Edit Colours... In the dialog box click "Define custom colours" and select your colour. In the bottom right hand corner there should be three fields named Red, Green and Blue. These are the three numbers you need. Put them into the Value field in the Edit String dialog box in order and with one space between each, eg "0 78 152". Click OK

To get rid of the flashing picture, or replace it with another one, this time instead of clicking Colours in the Registry Editor, click Desktop, right click on the Wallpaper key and go Modify. To get rid of the picture delete what's in the Value field and click OK. To change the picture, replace the value with the full file path of the picture you want to add, eg C:\WINDOWS\Web\Wallpaper\Acer.BMP. Click OK.

Hope this sorts everything out. Harryboyles 12:21, 24 July 2006 (UTC)

popups

i have a computer that isnt connected to the internet, and its anout 2yrs old so pop ups to renew the virus thing that came with windows keep coming up. Is there anyway to stop these pop ups?

thanks --86.130.255.231 18:39, 23 July 2006 (UTC)

I'm assuming you have Windows XP with SP2, although this might work with an earlier Service Pack, I can't remember. It might also work with Server 2003. Go to Start->Control Panel->Security Center. In the 'Resources' list on the left of this new window, click the 'Change the way Security Center alerts me' link. Uncheck the Virus Protection item, then click OK. However, it is good practice to have a virus scanner even on an offline PC, as viruses don't just propagate via the net, they can spread on things like floppy disks, and presumably, flash drives too. CaptainVindaloo ^{t c e} 20:55, 23 July 2006 (UTC)

Floating boxes (CSS)

I have a question regarding CSS and "float" property. Consider the following example:

<div style="border:1px solid black; padding:2px; float:left; width:150px">Left-floating</div><div style="border:1px solid green; width: 100%">Full-width</div>

It generates:

Left-floating

Full-width

The question is, how do I prevent the boxes from intersecting? I know I can use table tags, but is there a way to do it using CSS? Conscious 21:32, 23 July 2006 (UTC)

Float means the "wrappable" items will wrap aroung the floating item. The div itself is not a wrappable item. So, you need to put a margin on the left of it. For what you appear to be trying to do, you will want the first box to be; position:absolute;top:0px;left:0px;width:150px; Then, the second will have margin-left:150px; The kicker (and why CSS sucks) is that your 100% width will mean that since you shifted it right 150px, it will stick 150px off the right side of the screen at 100% width. The simple solution is to replace 150px with a percentage, like 10%. Your first box is 10% width and the margin-left of the second in 10%. Then, make the second box 90% width and it will rest nicely on the right side of the screen. All in all, tables are MUCH easier to work with but they are supposed to be evil now. Until CSS gives you the ability to simply have a header, left menu, and footer, I'm sticking with tables. --Kainaw ^(talk) 21:48, 23 July 2006 (UTC)

The desired result is something like:

Left-floating

Full-width

Thank you for your answer. So, are you basically saying that it's impossible to achieve the same with CSS only? Conscious 21:53, 23 July 2006 (UTC)

In Mozilla, you can define top-bottom-left-right positions, which makes it easy to put boxes exactly where you want them. In my experience, IE ignores right and bottom if either top or left is set. Then, there is the issue of overflow. What if I want a footer just below the main content. If I put the bottom of it at the the bottom of the screen, it will be at the BOTTOM of the SCREEN. Not the bottom of the page if the page is longer than one screen. With tables, you know the last table row will be at the bottom. You know the menu column will expand as necessary. You know the main content cell will be as tall and wide as you like. You just have a lot of control with tables. With divs and CSS, you have a lot of guesswork and hope that it looks nice from one browser to the next. Now, where's the CSS-genius who is going to tell me I'm stupid and clue me in on the magic CSS setting that makes divs work like they should? --Kainaw ^(talk) 21:59, 23 July 2006 (UTC)

Left-floating

Full-width

See, I just achieved the same with CSS only ☺ (while table is considered evil, display: table isn't). By the way, AFAIK it (predictably) does not work in MSIE. --cesarb 22:19, 23 July 2006 (UTC)

Oh, I've just discovered that in IE the "Full width" box is rendered below the "Left floating" box. The example for IE is:

<div style="border:1px solid black; padding:2px; float:left; width:150px">Left-floating</div><div style="border:1px solid green; width: auto">Full-width</div>

Left-floating

Full-width

Conscious 22:05, 23 July 2006 (UTC)

OK, I was joking with the display: table example above; try this one.

Left-floating

Full-width

--cesarb 22:24, 23 July 2006 (UTC)

Thank you; a good idea with a margin. Conscious 19:08, 24 July 2006 (UTC)

You can do it in CSS (well, almost)

Here's (roughly) how to do your two column layout in CSS - you'd have the two columns as floating divs inside a master div, like this:

<div>
  <div style="border:1px solid black; float:left; width:15%;">Left-floating</div>
  <div style="border:1px solid green; float:left; width:84%;">Full-width</div>
</div>

giving:

Left-floating

Full-width

You'll notice that, if the browser page gets very narrow, the blocks "delaminate". In some cases, that might be something you want. Look at http://www.mcwalter.org/images/ and resize your browser horizontally.

But if you don't like that, you can hardwire the width of the master DIV:

<div style="width:60em; float:left;">
  <div style="border:1px solid black; float:left; width:15%; margin-right:0.1em; ">Left-floating</div>
  <div style="border:1px solid green; float:left; width:84%;">Full-width</div>
</div>
<br clear="all">

Left-floating

Full-width

I'll be the first to admit that the CSS block layout model is complicated, and that the "delaminate" thing can be annoying and difficult to avoid (I seem to have avoided it on http://www.mcwalter.org, although I can't immediately remember how I did it). Right now I don't have a total table-replacement solution in CSS, but that's partially due to my inadequate understanding of the layout model, and partly due to browser bugs. -- Finlay McWalter | Talk 13:49, 25 July 2006 (UTC)

Torrent

Let's say I wanted to create a torrent, not to go on a big website like IsoHunt or The Pirate Bay, but just so a few people I personally know could get a link to it. How would I go about doing that? zafiroblue05 | Talk 01:48, 24 July 2006 (UTC)

Azureus has a built in tracker, so you can make your own torrents. I believe UTorrent does as well, although I have never used Utorrent. See here, and here for more information about Azureus. Debigulator 02:18, 24 July 2006 (UTC)

If it is just a few people why use a torrent? Jon513 20:26, 24 July 2006 (UTC)

If you personally know them, why use a torrent as the above person mentioned? --Proficient 11:54, 26 July 2006 (UTC)

Horizontal Scrolling in a browser window

When I search the internet for "horizontal scrolling" and "HTML" I get many pages saying to avoid horizontal scrolling. I agree, but....here is what I want to do:

• I need to use a display that can show 1280 pixels horizontal
• I need to use a browser to display two images side-by-side, each image has a width of 640 pixels.
• I have to use a browser running under Windows XP.
  I have no problem getting this to work with Macintosh OSX. In OSX I can slightly increase the width of the browser window until both images display side-by-side. However, using either Explorer or FireFox in Windows XP, the two images always are shown stacked vertically, not side-by-side. When I try to increase the width of a browser window by draging the window's side border, nothing happens.
  What is a simple way to get this to work in Windows XP? I do not mind horizontal scrolling.
  This is the HTML code I am using to display the two images:
  <img src="image1.jpg" border="0" height="480" width="640">
  

<img src="image2.jpg" border="0" height="480" width="640">
--JWSchmidt 14:34, 24 July 2006 (UTC)

Use a table: <table><tr><td><img src="image1.jpg" border="0" height="480" width="640"></td><td><img src="image2.jpg" border="0" height="480" width="640"></td></tr></table> --Kainaw ^(talk) 14:56, 24 July 2006 (UTC)

• Thanks! That works great. --JWSchmidt 15:35, 24 July 2006 (UTC)

annoying : my azerty keyboard works as qwerty on foreign sites,like these

Hello, I am experiencing an annoying problem, and thank god for the recent creation of this desk.

In Belgium and France we use Azerty keyboards instead of Qwerty. Usually there is no problem, but today I went to IMDB, www.mathlinks.ro and Wikipedia itself, and everything is interpreted as Qwerty : when I press the 'a' button on my keyboard it gives a 'q' on screen. I went to the website www.vrtnieuws.be, which is Belgian, and I had no problems at all.

I have had this problem before but I think this is the first time I have it on all foreign sites. It is worth nothing that the last time it just seemed to disappear the next day.

So what do you think?

Evilbu 15:51, 24 July 2006 (UTC)

This is a tricky one. I would check that everything looks okay under 'Keyboard' and 'Regional and Language Options' in the Control Panel. What browser are you using ? Robmods 16:41, 24 July 2006 (UTC)

the quick brown fox jumps over the lazy dog : there my keyboard works perfectly fine now! I do not understand. I use Internet Explorer, my language is Dutch. Evilbu 17:47, 24 July 2006 (UTC)

Computers

When was the first computer built?

Did you check the article computer? Did you see the link to history of computing? --Kainaw ^(talk) 17:32, 24 July 2006 (UTC)

Actually, History of computing hardware would probably be more useful in this case. --ColourBurst 17:40, 24 July 2006 (UTC)

Depends on what you mean by "computer". --Serie 22:59, 24 July 2006 (UTC)

The ENIAC was the first wide-scale electronic computer, which is probably what the person asking the question was looking for, but I could be wrong. --Proficient 11:56, 26 July 2006 (UTC)

During World War II a "computer" was a person, most likely a woman, and was definitely not a machine. It would be impolite to say they were "built". Devices for computation might include the abacus, the Antikythera mechanism, or even Newgrange. Probably what you want is the article on the history of computing hardware. --KSmrq^T 18:22, 26 July 2006 (UTC)

quotation marks

Why are some windows' registry commands (data) enclosed in quotation marks?

If the data is a test string with one or more spaces in it, the quotes may serve to mark off the beginning and the end, otherwise the spaces may confuse things. Also, even if there are no spaces, some programs may write the data as text strings instead of numberic values. I'm not sure if that explains all the uses of quotes though... Digfarenough 20:19, 24 July 2006 (UTC)

In programming especially, strings are often enclosed in quotation marks to differenciate from variables. For example if you wanted to use the phrase "Tigers are big", but you already had three variables names, tigers, are, and big, which would the programming language think you were wanting to use? In Visual Basic, strings and phrases are enclosed in quotes to distinguish from variables. Harryboyles 22:30, 24 July 2006 (UTC)

All that aside, in the Windows registry, setting a value in quotation marks means disabling it. This is most commonly used in the section of the registry which controls what programs run at startup - by enclosing the program in question in quotation marks, you are preventing it from running at startup, but the value is still there so that you can easily re-enable it. — QuantumEleven 07:28, 25 July 2006 (UTC)

You learn something new every day. :-) Harryboyles 07:56, 25 July 2006 (UTC)

Firefox doesn't work with YTMND

and other sites with music/videos either. The bar on the top comes out and says I need additional plugins to view this page, then it says to manually install Quicktime, but I alredy have both Quicktime and WMP. It works fine in IE, though, and I have no idea what causes this Wizrdwarts (T|C|E) 18:23, 24 July 2006 (UTC)

If you had QuickTime installed before you installed Firefox, you'll probably need to re-install QT so that the proper plug-ins get put in the right places. You might get some help starting here. --LarryMac 19:41, 24 July 2006 (UTC)

Install Plugins. --Proficient 11:56, 26 July 2006 (UTC)

Proficient: I already installed them, but thanks anyways!

LarryMac: Thanks! It works now! Wizrdwarts (T|C|E) 23:14, 27 July 2006 (UTC)

Complexity...

Is it possible (in theory) for something to design something more complex than itself? Could I build a computer that would tell me how to program a computer to do something? If that is not clear, an example is:

1. I want to do task X.
2. I build a computer, A.
3. Computer A is not complex enough to complete X.
4. Computer A is complex enough to design computer B.
5. Computer B can solve X.

Is this banned by some fundamental rule of the universe/logic/computing/something else? Or would it be (theoretically) possible? —Daniel (‽) 19:54, 24 July 2006 (UTC)

I can't offhand think of any reason this couldn't happen. In fact, there's a fairly popular theory that that's how we'll eventually be rendered obsolete - intelligent machines will design more intelligent machines in an infinite cycle, and naturally they won't have any reason to keep us around. As a matter of fact, there's a fun book based on this premise. Black Carrot 20:04, 24 July 2006 (UTC)

Consider X = "compute 1,000,000 digits of π in a second", A = "human", B = "computer". Conscious 20:18, 24 July 2006 (UTC)

you built a human!? Jon513 20:22, 24 July 2006 (UTC)

It's simple. It just requires another human. --Zemyla^t 20:27, 24 July 2006 (UTC)

Of an opposite sex, you know. Conscious 20:37, 24 July 2006 (UTC)

I dunno, if Computer A is a universal computer (Turing equivalent), there ought to be no task that is too complex for it in theory. There are two other possibilities that come to mind, though: Computer A may be a finite state machine and the task may be to recognize a context-free grammar, so Computer A would not be able to perform the task (because it is not a universal computer).My guess (without proof) is that Computer A would not be able to build, e.g., a pushdown automata that could recognize the context free grammar. Another possibility is that Computer A has too little memory to perform the task (e.g. a task requiring that 2KB of values all be in memory simultaneously, whereas Computer A only has 1KB of memory). In that case, my intuition is that it would be possible for Computer A to design a Computer B that would be able to complete the task (assuming Computer A is universal). It's a good question though, I've pondered similar things in the past. Digfarenough 20:26, 24 July 2006 (UTC)

Yes. It is expected of AI programs to produce "logical" code that more complex than the AI code itself. For example, one of my undergad projects was to develop a distributed AI engine. That was very easy. Then, to test it, we first made a rating test to tell it if it was doing well at summing integers. Designing the rating test was difficult, but we got the hang of it. Then, we developed a test to tell it if it was doing well at sorting integers. After a year of fine-tuning the test, it developed a rather complex distributed sorting algorithm - though it wasn't the fastest one, it was complex (we never added speed to our test). Side note here: If you want a program to develop something very complex without explicity telling it how to do it, you need to provide some form of test that rates the end result. That test can be very difficult to develop - possibly more complex than the program being developed. --Kainaw ^(talk) 23:22, 24 July 2006 (UTC)

I think what you are referring to is called a genetic algorithm. It searches through a list of possible solutions to a given problem and combines them at random to produce new solutions. It then uses a special test (called a fitness function) to choose the best solutions. These solutions are htne allowed to be combined again. It has been proven that given a good fitness function, the algorithm will converge to an acceptable solution after a given number of generations. However, it is possible that it will converge to a local peak in the solution space rather than to the best solution. My MS thesis ivolved the use of genetic algorithms and the example I used found a maxima on a graph of a sine function. It convereged to a solution after about 6 generations.

Another example from AI would be the use of neural networks, which construct algorithms to solve a given problem based on some training data. The algorithms themselves usually are more complex than the program used to construct the neural network. --Max

Yes, that's impossible. Specifically here:

Computer A is not complex enough to complete X, yet is complex enough to design computer B which can complete X. That's not possible - if it could make a machine that can do X, it can also do X itself.

Be very careful when defining 'complex' and don't define it as speed. A human, if you spent enough time, can calculate 1 billion digits of Pi, yet normally you would call that impossible - it's not, it's just slow.

Look at the history of computing: have humans EVER created a machine that can do something that humans can't do? It's never happened before, and it never will. (And remember don't talk about speed, or silly things like fine motor skills or strength, I mean actual creative activities.)

The article on Technological singularity talks about this, but in my opinion does so incorrectly. It starts by assuming your conjecture is possible, without ever actually proving it, or even doing something as simple as suggesting how it might be done. I wrote a paragraph about the problem, but it was removed from the article since I didn't have a site-able sources. 71.199.123.24 21:46, 27 July 2006 (UTC)

DVD+RW to Computer

How to you upload data from a DVD+RW to a computer, for a use in a program (such as Windows Movie Maker). Hello32020 22:55, 24 July 2006 (UTC)

Insert the DVD+RW disk into your computer's DVD drive (which needs to be +RW capable). View the disk contents as a window. Copy the contents to the folder of your choice on the hard drive. --Canley 23:46, 24 July 2006 (UTC)

Magical onClick="return (false);"

I used MS Word to make a few short HTML files. I saved the files as plain text and gave them the extension .html
These HTML files worked fine on my computer. In particular, they had working hypertext links such as:
<a href="Images Page 2.html">Next page of images</a>
I sent these files as email attachments to some other people. The same HTML files now on their computers , mysteriosly contain code for the links that looks like this:
<a href="Images Page 2.html" onClick="return (false);">Next page of images</a>
Question: where did the inserted onClick="return (false);" come from? How can I avoid this in the future? --JWSchmidt 22:57, 24 July 2006 (UTC)

MS Word added it. It is a word processor, not a web page design tool. So, you shouldn't expect it to produce useable HTML. --Kainaw ^(talk) 23:17, 24 July 2006 (UTC)

next time use Nvu. Jon513 23:35, 24 July 2006 (UTC)

• I have in the past used BBEdit Lite and Netscape Communicator. Thanks for the link to Nvu....I had no idea that it exists. --JWSchmidt 00:45, 25 July 2006 (UTC)

How much space would wikipedia take up?

How much space does wikipedia take up (including all the history and discussion files)? — Preceding unsigned comment added by 16:26, July 25, 2006 (talk • contribs) 141.149.236.64

See Wikipedia:Database_download and http://download.wikimedia.org/. As of September 2005, a compressed full database dump (text only), including old page versions, is about 40GB. The compressed dump with only current revisions is about 1.2GB (900MB excluding talk and user pages). -- Koffieyahoo 07:09, 25 July 2006 (UTC)

Uncompressed, the full database dump (text only) is about 20 times the size of it compressed. This means that it's about 800 GB. Note this does not include images because of legal reasons. To download the images is about 76 GB compressed. Harryboyles 07:21, 25 July 2006 (UTC)

Are the images truly compressed? IIRC they are archived but not compressed (since all the image formats already have their own compression, doing any extra compression wouldn't gain much). --cesarb 15:47, 25 July 2006 (UTC)

On the page Wikipedia:Database_download it says under "Dealing with compressed files" that "Approximate file sizes are given for the compressed dumps; uncompressed they'll be significantly larger." Just remember that with the revisions and previous images that have been reverted, that many are similar or the same, meaning that you'd save space because of the sameness of the files, if that makes senseHarryboyles 03:21, 26 July 2006 (UTC)

Need help in senior project

hi all, as mentioned in the heading,could anyone suggest me a topic for my senior project which is necassary for the graduation,as i am a final year student doing BSc. in Computer Engineering,Im willing to implement a networking software(or something related to networking). Any idea or suggestion will be appreciated. You can send me on my yahoo account: [removed to prevent spam]-- FOZ

don't post your email here. It is a sure way of getting spam. Jon513 11:21, 25 July 2006 (UTC)

Shouldn't you ask your professor on what kinds of projects are appropriate? --ColourBurst 23:18, 25 July 2006 (UTC)

Regarding asking my professor abt the project,the semester is going to start after two months from now,and i wanted to begin working on the project from now, so by the time the semester begins i will be done with the preparation part(finding good material for the project).-- FOZ

Word macro keyboard shortcuts

How does one get a list of keyboard shortcuts assigned to macros in Word? There is an option to do this for built-in commands, but I can't find out how to do it for macros - not even one macro at a time. Help gratefully received, thanks. -- SGBailey 11:22, 25 July 2006 (UTC)

does this help?Jon513 12:24, 25 July 2006 (UTC)

Thanks, but no it doesn't help. That is a list of standrad commands - and I know how to get that list anyway. What I am after is a list of the keycodes that have been assigned to assorted macros. -- SGBailey 13:59, 25 July 2006 (UTC)

If you are happy with running VBA code - this may help

   Dim i as integer
   For i = 1 To KeyBindings.Count
       Selection.TypeText KeyBindings.Item(i).KeyString & vbCr
       Selection.TypeText KeyBindings.Item(i).Command & " " & KeyBindings.Item(i).CommandParameter & vbCr & vbCr
   Next

I've not done any real testing - but it should point you in the right direction

--Worm 14:14, 25 July 2006 (UTC)

Looks good. Thanks -- SGBailey 15:27, 25 July 2006 (UTC)

copy into first partition

I've got several hd's on my computer. On one I've got my 'main' OS, Suse 9.1, on the second partition. Now I wish to have Win98 on the first partition, which is now formatted as ntfs, which I would have to change to fat first. Installing it would screw up Suse (right?), but I've got an old version of Win98 that I could copy there. This works with copies - I've done that loads of times. I'm not sure if copying an OS to a different drive will work, but it's the exact same type, so it might just work. Anyway, what I want to know is if doing this will affect the boot process. This will leave Suse itself alone, but it might affect the boot sector and/or the boot manager (grub). I know a bit about computers, but I'm no expert, especially when it comes to practicalities. So I don't want anything to get in the way of starting my main OS. So is it safe to do this? And does it matter if I do this from the Suse installation itself or from another OS (Ubuntu) on another hd? And will the reformating from ntfs to fat have an effect? DirkvdM 11:22, 25 July 2006 (UTC)

Installing Windows doesn't "screw up" SUSE. It simply overwrites the bootloader with its own. You don't have to restore it from SUSE, since you won't be able to boot from it anyway. This guide should help you out. Try the Using the LiveCD and Overwriting the Windows bootloader section. I'm not sure what would happen if you tried to convert NTFS to FAT32, though. --Optichan 19:17, 25 July 2006 (UTC)

There is no way to 'convert' an NTFS to FAT disk, you have to wipe it and reformat that disk. — QuantumEleven 06:57, 26 July 2006 (UTC)

Well, it is possible to convert ntfs to fat with Partition Magic. But I want to format it anyway. The question was if that affects the boot sector. And I understand it does. DirkvdM 10:03, 26 July 2006 (UTC)

Kodak camera with movies

My Kodak DX4530 takes .mov movies which I have to play back through Quicktime. How can I determine what version of .mov they are? What software is recommended to convert a .mov to a .avi or .mpg - (I'd like to play it back on windows media player)? -- SGBailey 12:03, 25 July 2006 (UTC)

.mov, like .avi, is a container format: it's a way of organizing data without saying anything about what format of data is inside. The most likely format for the movie data is motion JPEG, which Windows Media Player can play. Since they're both container formats, it's possible to convert between them without loss of data. I've used a freeware program called "trmoov" to do this in the past: search Google for it. --Serie 22:17, 26 July 2006 (UTC)

July 25

DCC Networking

I just bought a laptop and I need to transfer files from my PC. I looked around a little bit and got the impression that all I needed to do was buy a cat5 crossover patch cable and connect both computers by their ethernet ports. So, I bought a cat5 cable and an adapter that makes it a crossover cable, plugged the two computers together... and nothing. The machine knew something was in the network cable (ethernet) port, because it usually says "a network cable is unplugged" and it was no longer doing that, but it said "limited or no connectivity" and I am stuck there. Both machines are running Windows XP (planned host computer is running xp home, and guest is running professional). I tried going through the network setup wizards, to no avail. I might have done them wrong somehow. I'm asking here because I can't find any decent tutorials, I know no one who knows anything about networking, and wikipedia hasn't failed me yet...

Any help is GREATLY appreciated!

your computers are probably looking for a DHCP service to give them an address, and likely neither has one, so they both end up with useless autoconfig addresses. Hardwire one to 192.168.0.20, the other to 192.168.0.21, set the netmask to 255.255.255.0 and you're off. -- Finlay McWalter | Talk 14:39, 25 July 2006 (UTC)

Wow, that was quick, thanks much... but where do I make those changes? I'm not computer illiterate, but I have never had to mess with networking in any way. Thanks again!

On Windows XP: "start" button at bottom left of screen -> settings -> network connections -> double click on the network adapter -> properties -> double click "Internet Protocol (TCP/IP)" in the scrolldown list -> select "Use the following IP address", type in ip address and subnet mask as mentioned above; ok/ok/ok to close everything. To restore DHCP (which you'll probably need to get to the Internet) select "obtain an IP address automatically" and "obtain DNS server automatically". Good luck! Weregerbil 15:49, 25 July 2006 (UTC)

Thank you, thank you-- I'm still wary, though. I'm away from the two computers in question now, but looking at the one I'm using here at work, also using XP, (just to see the path, of couse, not to change anything) I try and follow the path. Start -> no "settings"; use control panel, get to network connections. Double click on the net adapter, go to properties and all I have is one tab that says "general" and no scroll down menus... Again, any and all help is greatly appreciated!

There should be a box with the title "This connection uses the following items:". It's there that you want to double click "Internet Protocol (TCP/IP)". If it isn't listed, click the Install... button, select Protocol and click Add... then you should find TCP/IP in there. From there you can follow the above instructions on setting the IP and subnet mask. 128.197.81.223 17:23, 25 July 2006 (UTC)

Hmm... I still cannot find it. I checked the list on "Add/Remove windows components" and there is nothing about TCP/IP... does that indicate something? Do I need some other piece of hardware or software to do this? If there are any good web tutorials, let me know! For as simple as it's been explained, this is driving me nuts... I also realize that this is not the tech support helpline, so I really do appreciate the help I'm getting!

Here is one tutorial. One thing to note is that, since you're at work, you may not be logged in as an administrator (as the link mentions) and so some options may not be available. Oh, also you don't have to do all the steps in that link, you should be ok stopping after step 9. Digfarenough 19:24, 25 July 2006 (UTC)

All right! I got home and connected the two, apparently; the "limited or no connectivity" message is gone... but now how do I actually do something with that? Can some one point me to a tutorial for setting up a network...? thanks much, again.

You ought to be able to share a folder or harddrive from the PC on a network and access it from the laptop using network neighborhood. Just right click on whatever you want to share, go to "Sharing and security" on the PC, click the radio button for "Share this folder", then click OK and see if you can find it somewhere in network neighborhood on the laptop. That's probably the easiest way. Digfarenough 21:01, 25 July 2006 (UTC)

Oh, I realized earlier that folder sharing might not actually work for you. What I personally use to do this sort of thing is sftp. You can download free software, openssh for the PC and, say, winscp for the laptop and run an sftp server on the PC using openssh (you can find instructons on setting this up online). Then you can connect to that sftp server using winscp (or your favorite sftp program) and download all your files. Digfarenough 17:09, 26 July 2006 (UTC)

If you need to transfer files, you can use other means, such as a CD/DVD/Flash Drive/etc. Or if you have a router, just share files or transfer them. This may not answer your question, but it's just a though. --Proficient 11:58, 26 July 2006 (UTC)

Wrong Driver for BT Keyboard

I have a pocket PC running Windows Mobile 5.0, and a bluetooth keyboard, but the keyboard only comes with a driver for Pocket PC 2003, and I am told by the PDA that the keyboard may not work because the driver was 'designed for a different version.' They keyboard is a Cygnet Bluetooth Keyboard. Where can I get an appropriate driver from/how can I make the keyboard work? Many thanks, --86.139.122.229 18:19, 25 July 2006 (UTC)

Did you check for updates at the manufacturer's website? --LarryMac 18:38, 25 July 2006 (UTC)

Computers and ITAR

Are new computers, intended to be used by a military contractor abroad, considered an export that is subject to the regulations of ITAR?

You need to define "used". As you state it, the computers will be owned by the U.S. military and therefore not be "exported" because the action of moving items to and from military bases and deployments is not referred to as an export or import. --Kainaw ^(talk) 20:10, 25 July 2006 (UTC)

Best way to study for Comp sci GRE

Can anybody offer any advice as to how to study for the computer science GRE? I have a few books with practice tests, but none of them offer any subject material to study. I've gone over most of the material in previous classes (besides algorithms, architecture, networking) but going over everything seems a bit overwhelming.

I remember two types of questions in the CSCI GRE:

One type was just math word problems. I didn't get the purpose. They were similar to: "If a harddrive has an average transfer rate of 120b/ms and an average seek time of 8ms, how long would it take to read a 12kb file assuming that the file is not fragmented?" They aren't complicating it. They are simplifying it - 8ms seek to find the start of the file and then 120b/ms after that until you read all 12kb.

The other type of problem was random definitions - again, I didn't get the purpose. They were similar to: "(insert some name you've never heard of)'s Theory of (insert some word you've never heard used in Computer Science) states that...(insert possible answers that are all very similar)." You have to take the practice tests and, if you get one wrong, Google (or Wikipedia) for it. --Kainaw ^(talk) 16:05, 26 July 2006 (UTC)

It was a while ago that I took it, but I recall there being some questions on databases and computer graphics which were never covered in any classes I took (luckily I'd learned a lot of that stuff on my own). There were definitely things like given two nested for loops, what would the output of a given block of code be, and some simple time complexity analysis problems. I also seem to recall a question about finite state machines. Basically they cover all sorts of ground, and more likely that not, there will be questions on there your classes haven't prepared you for. The best thing to do is just take practice tests and see what you don't know, as Kainaw suggested. Digfarenough 16:29, 26 July 2006 (UTC)

Running out of memory storage

hi all, someone has told me that when I delete data (file, folder etc) stored on my computer, it is erased from the hard disk( physical area in CPU) leaving that area(certain blocks) useless i.e connot be used anymore for the purpose of the data storage, so my question is how can I shift those blocks at the end (In other words, put the nonempty blocks together) in order to fill the gaps in between. -- FOZ

I think you might be a little confused here but I'll see what we can do:

• First of all, when you delete something off your computer, it doesn't make those sections of the hard disk (sectors) useless. Otherwise the hard drive manufacturers would be ten times as rich and we'd be ten times as poor. When disk errors occur, some file systems, like NTFS render the sector unuseable to prevent more data corruption. But normally, when you delete something, you can use the space again.
• Second, the CPU and hard disk are not joined together "erased from the hard disk( physical area in CPU)". The two communicate to each other, with each doing their separate tasks but working together along with other parts to form the computer.
• Third, ("how can I shift those blocks together in order to fill the gaps in between") when hard disks add data, they put in the first available spot. Even if it's to small to fit, they do. The remaining data gets put in the next available place. Over time, bits of files get scattered all over the disk making the hard disk work harder (no pun intended). This is called fragmentation. Defragmentation is where the hard disk rearranges the data back into order, like when a librarian puts all the scattered books into their correct place on the shelf. Windows comes with a free defragmentor under Start, Programs, Accessories, System Tools, Disk Defragmentor. There are commercially available defragmentors which do a much better job.

Hope this helps. Harryboyles 07:36, 26 July 2006 (UTC)

Thanx Harryboyles, it realy helped me alot.-- FOZ

There are some other commercial utilities that will defragment. --Proficient 12:00, 26 July 2006 (UTC)

With Microsoft Windows operating systems, the default behavior when deleting something using the GUI is to place it in the "Recycle Bin," so indeed, the disk space is not immediately freed up. This scheme allows one to recover files that have been accidentally deleted, but it's usually a good idea to empty the recycle bin regularly so that the space is, indeed, freed up. --LarryMac 13:47, 26 July 2006 (UTC)

Music software

Are there any softwares that allow you to edit music? For example i have a music file and I want to edit it so taht the vocals could be cut out and the piano part could be cut out? (more importantly are there any open source softwares like that?) Thanks!

Audacity is a great music editing open source program. If the piano part and vocal part are on the same track as the other parts, they cannot be edited out, but no program can do that once all of the parts are combined. —Mets501 (talk) 09:13, 26 July 2006 (UTC)

There's a list at Digital audio editor. But as Mets501 pointed out, what you want specifically isn't easy. Hoever, if the quality doesn't matter too much (eg you want to play and sing along for practise) and the voice is in a specific frequency range (it usually is) you might filter out that range, hoping not too much of the other instruments will be removed in the process. With a piano this would be a lot more difficult because a piano had a much wider range. DirkvdM 09:58, 26 July 2006 (UTC)

Often (but not always) the main vocals are mixed right in the middle of the stereo field, so if you invert one channel and add it to the other, the vocals will disappear (most programs have an option to do this, in Adobe Audition it's under Amplify, as I recall). However, if stereo reverb was used on them, you'll still get some leftover reverb of the vocals. For a given song, there's an easy way to check this: play the song on some system with headphones plugged in, then slowly pull the headphone plug out.. at some point the sound will get weird because the channels will be adding in the way described above and anything in the center of the stereo field will disappear (try it with Nine Inch Nails - Piggy for a very clear demonstration). DirkvdM is right about filtering though, especially with piano which has a lot of higher harmonics, it'll be hard to get rid of it all. One other possibility: if the producer of the album or the musicians were really lazy, they might have just recorded the piano part for the verse and chorus once and then repeated it in the song, so if you could find a section of the music with just the piano playing that part, there's a small chance you could invert both channels and add it on top of the same part elsewhere in the song to cancel some of it out. The chances of that working are very slim, though. Digfarenough 16:38, 26 July 2006 (UTC)

Circumventing Blocking

When I'm at school I sometimes want to use my free time on the school's computers to play online games or browse pages, however these are often blocked. Our school's blocking software (provided by the NSW education dept) is quite smart and won't allow me to circumvent it by looking at Google's Cache or translating the page from english to english. Are there any other simple ways that allow someone to circumvent system blocks? --AMorris (talk)●(contribs) 12:19, 26 July 2006 (UTC) (though it's probably not the wisest idea to put my name to this q.)

My friend searched the internet and looked for anonymous proxies and managed to get onto eBay, despite Websense blocking it as "internet auctions". Anonymous proxies could be one way to go, but these are normally also blocked as "proxy avoidance". Worth a try though. Iolakana|^T 12:59, 26 July 2006 (UTC)

Indeed. Proxies seem the easiest solution. --Proficient 15:54, 27 July 2006 (UTC)

I keep a list of links for a situation like this at my 204 page. Encrypted ones are prefered. And a lot of times all you have to do is stick the "s" on the end of "http" to use a site. If you need help with something like this again, just ask on my talk page. — The Mac Davis] ญƛ. 21:29, 27 July 2006 (UTC)

WikipediA font?

What font and settings are used for the "WikipediA" in the logo??--Sonjaaa 15:12, 26 July 2006 (UTC)

Not sure. Looks like a custom font to me (I don't think I know any with a crossed W like is shown in the picture). It is similar to "CAC Camelot" in small caps, however.—Mets501 (talk) 17:51, 26 July 2006 (UTC)

I think it's Garamond. This question has been asked before. Neat; I've never noticed that the 'A' was capitalized.--epf 22:02, 26 July 2006 (UTC)

It's Hoefler Text. It's a beautiful font, incidentally, particularly for long documents. Print out a school paper in Hoefler Text and it looks wonderfully professional - like a novel, even. Incidentally, I believe Hoefler Text is available on Apples but nowhere else (unless you pay an exorbitant fee.) zafiroblue05 | Talk 23:01, 26 July 2006 (UTC)

I use the Colongne skin and its all capitals in Times New Roman, white. — The Mac Davis] ⌇☢ ญƛ. 20:21, 27 July 2006 (UTC)

Sunni vs Shia

I have somewhat of an idea about the difference between these two groups, but from what I know I cannot understand why the hate each other. Anyone have an answer?

You might want to ask at the Humanities or Miscellaneous Ref Desks, this is hardly a Computing question. --LarryMac 16:49, 26 July 2006 (UTC)

Dunno, I think I've heard the Sunni like KDE but the Shia prefer GNOME... but it's some ancient dispute that I don't know the details of. When will they learn you can run both at the same time? Digfarenough 16:58, 26 July 2006 (UTC)

No, the Sunni prefer Unix, the Shia MS-Windows. User:Zoe|^(talk) 17:48, 26 July 2006 (UTC)

Isn't there a radical wing of Sunnis that prefer Macs? --Kainaw ^(talk) 22:34, 26 July 2006 (UTC)

First of all who have told you that these two parties hate each other??? they realy dont...-- FOZ

And second of all .... ? DirkvdM 06:24, 27 July 2006 (UTC)

Sync sent items on PDA

I have Windows Mobile 5.0. Is there any way I can sync emails sent from my PDA over Wi-Fi with the 'Sent Items' folder on Outlook on my PC when I syuc the two devices. Many thanks, --

How might I create a Dimensional analysis program?

I'm very impressed how Dimensional analysis and Buckingham's pi theorem can be used to create a mathematical formula (or set of formulas) just from specifying the variables you think might be relevant. (The common example used is the formula for a pendulum).

I think it would be fun to have a software program that could take as input the user supplied list of variables, and output a formula (or more probably, a list of formulas) obtained by using Dimensional Analyis and the Pi theorem.

I am only an amateur programmer now and then, and I cannot think how I would begin to program such a thing.

Could anyone suggest how this might be done please? I suppose the problem can be broken down into how to represent the data and constraints, and how to transform them in accordance with Dimensional analysis and/or the pi theorem.

Further constraints that could be added are making the formulas consistent with levels of meaurment used (eg. ordinal etc), and with intensive and extensive measures (eg an extensive measure divided by an extensive measure gives an intensive measurement (I think)).

Thanks. --81.104.12.4 19:11, 26 July 2006 (UTC)

You need to specify the problem a bit more, I think, and then the algorithm should be more obvious. If what you're doing is taking a set of physical dimensions (such as "power" or "speed") and attempting to express one solely in terms of a product of powers of the others (which is the usual task in dimensional analysis: it is assumed that the one quantity is proportional to some power of each other one), you can express it mathematically by defining each dimension in terms of some basis of dimensions (e.g., the SI base units) and making each a vector of the powers of the basis dimensions. For example, using the basis of just {mass, length, time}, we can express speed as $\{0,1,-1\}$ and power as $\{1,2,-2\}$. Multiplying dimensions corresponds to adding vectors (since the vector components are exponents, and multiplying adds exponents), and so raising dimensions to powers corresponds to scalar multiplication of the vectors. Then we can state our problem as ${\vec {v}}_{0}=\sum _{i}p_{i}{\vec {v}}_{i}$, or $v_{0j}=v_{ij}p_{i}$ (with Einstein summation), where ${\vec {v}}_{0}$ is the desired result dimension, ${\vec {v}}_{i}\;(i>0)$ is one of the "source" dimensions, and $p_{i}$ is the power (possibly 0) to which the ith dimension should be raised. Since all the v-quantities are known, this is a standard linear system that can be solved with basic linear algebra.

For your pendulum example, we take the dependent dimension as time ($\{0,0,1\}$), and the candidate dimensions as length ($\{0,1,0\}$), mass ($\{1,0,0\}$) and the acceleration of gravity ($\{0,1,-2\}$). The system then looks like ${\begin{bmatrix}0&1&0\\1&0&1\\0&0&-2\end{bmatrix}}{\vec {p}}={\begin{bmatrix}0\\0\\1\end{bmatrix}}$, which has the solution ${\vec {p}}=\{{\frac {1}{2}},0,-{\frac {1}{2}}\}$. This corresponds to $T=L^{\frac {1}{2}}m^{0}g^{-{\frac {1}{2}}}={\sqrt {\frac {L}{g}}}$, which is of course the correct result to within a constant coefficient that we were not hoping to discover.

I hope I haven't ended up destroying your desire to write such a program by reducing the problem to well-understood mathematics! I'm afraid there just isn't much of an interesting algorithm here unless you consider more complicated analysis that may or may not be feasible to automate. Perhaps you could hew closer to the π theorem and look for dimensionless quantities in terms of all the variables (but then you're computing the null space of a slightly larger matrix, which is a somewhat harder problem). In any case, hope this helps. --Tardis 06:50, 27 July 2006 (UTC)

What pocket-sized thing best to read ebooks on?

There are lots of books listed in Project Gutenberg that I would like to read. However it is not very comfortable sitting up by a desktop computer reading them, nor would I want to try to use a laptop to try to read them in bed.

I would like something that could fit into a large pocket, that I could comfortably read in bed or on the train. Something that can cope with .txt files. Ideally, something not too expensive.

What specific brand of device would people recommend please?

(By the way, I did read one book by printing out the text in tiny type in two columns onto sheets of paper, but it was too tedious a method to do again.)

Thanks. --81.104.12.66 20:33, 26 July 2006 (UTC)

Some sort of PDA would be what you are looking for. Some sort of cheap Palm based device would probably be cheapest, but every model should cope with something as simple as a text file. --Robmods 21:16, 26 July 2006 (UTC)

I suggest a PDA with a black-and-white screen and no backlight. A backlight causes eyestrain after a while, and color displays require a backlight. As a side benefit, the lack of a color screen and backlight will triple the expected battery life. For reading in the dark, get a headlamp.

Personally, I use a Palm Zire 21, which cost me $100 new. The model's been discontinued, but you should still be able to find it in stores. Alternatively, you could look for one of the older Palm "m" models which uses standard AAA batteries rather than the integrated lithium battery of the Zire 21. --Serie 22:25, 26 July 2006 (UTC)

With PDAs, see if you can try them before you buy - I have a Palm Zire (very old), and its display resolution is a bit too low for comfortable reading, as I can't get many words on one line. Also, check if it supports longer text files - most PDAs ought to, but better to check (for instance, mine only supports a few kB of text in a single file, but, then, it is somewhat ancient). However, I echo the advice about black and white screen and no backlight - you will save a lot on battery power, and unlike fancier PDAs, my Zire will easily run for a month or more on one battery charge. — QuantumEleven 06:30, 27 July 2006 (UTC)

Perhaps you can copy it to your cell phone. --Proficient 15:55, 27 July 2006 (UTC)

swapping DIMMs

My Dell Inspiron 5100 with 384K memory crashed and then mostly it wouldn't start up again, or it would start and fail to completely boot, or it would boot and fail quickly in some application. I swapped the 128K and 256K DIMMs in the two sockets, and it has been working now for two days. What made the difference? Can I have any confidence that this "solution" will last? Thanks, Halcatalyst 22:36, 26 July 2006 (UTC)

question about network admins..

Do network admins of major US corporations have tools that will alert them of strange behavior on their intranets, such as a user slowly siphoning off data from the intranet onto a hard-drive and from there, uploading it onto a random ftp site?

I can say that those tools exist, but that doesn't mean that they are being used. I have a real-time monitor for the status of my servers (if they die, I get an email every 5 minutes until I get it fixed). As for usage statistics, I get a summary email at the end of every day. --Kainaw ^(talk) 01:00, 27 July 2006 (UTC)

hmm..interesting. Thanks1

not showing gmail

I run XP SP 2. When I visit gmail via either ie 6 or the most recent firefox, I can log in, but after page says "loading," all I can see is a blank page. I suspect the problem may be a setting in my firewall (Kerio personal ed.) Thank you. Amanaplanacanalpanama 23:51, 26 July 2006 (UTC)

for me it takes a bit of time, how long do you wait? Jon513 00:29, 27 July 2006 (UTC)

I would say longer than should be expected for the website to load. I've probably waited for 10 minutes. --amanaplanacanalpanama 02:33, 27 July 2006 (UTC)

I sometimes have that problem when I try to access gmail from work (all kinds of firewalls and proxies in the way). I'll see "loading" in the upper right (in red I think). But if I just do a refresh, then I see Loading in the upper left, in black, and it works. Not very scientific, and definitely original research, but I thought I'd mention it. --LarryMac 14:46, 27 July 2006 (UTC)

Perhaps you are using Firefox with the NoScript extension. Allow Google. Or perhaps a firewall is disallowing access. Make sure you have the correct plugins. --Proficient 15:57, 27 July 2006 (UTC)

Thank you very much for your input, LarryMac and Proficient. I have tried refreshing specifically and it doesn't help. I don't think it is a firefox problem because ie does the same thing. I'll have to try some of Proficient's other suggestions.--amanaplanacanalpanama 17:41, 27 July 2006 (UTC)

Thank you also Jon513.--Amanaplanacanalpanama 17:43, 27 July 2006 (UTC)

Ubervisor

I'm trying to find any source for article Ubervisor, but failed to find any. Article in IBM Systems Journal (linked in article) do not contain such term. Is this original research? --89.104.121.156 23:55, 26 July 2006 (UTC)

Seems like a protologism coined by some blogger. -- Koffieyahoo 01:33, 27 July 2006 (UTC)

FTP

i would like to know how you use FTP and why you would use it please.

Have you read our article File Transfer Protocol? —Keenan Pepper 01:12, 27 July 2006 (UTC)

Program for programming in multiple languages

Is there any easy to use, easy to install program out there that will let me develop and test programs in multiple programming languages. I've heard that Macintoshes come with these things installed on them, but I'm not using a Mac.

I'm not sure what you want this program to do, exactly. Are you looking for a multi-language integrated development environment? Try Category:Integrated development environments. —Keenan Pepper 02:15, 27 July 2006 (UTC)

You can program in assembly and decompile to just about any language you like. Realistically, there is no pseudo-language you can use because the important differences between different languages require completely different programming structures. You can write code that looks almost identical in multiple languages, but it will likely run poorly in all of them. --Kainaw ^(talk) 14:50, 27 July 2006 (UTC)

Can you suggest an software to remove voice from musics?

please tell me one

This has already been answered, see Wikipedia:Reference desk/Computing#Music software. Short version - unless under very specific circumstances, it's very hard to do. — QuantumEleven 06:26, 27 July 2006 (UTC)

I don't see how it is possible without the audio already in seperate tracks. — The Mac Davis] ญƛ. 20:20, 27 July 2006 (UTC)

It's possible: XMMS has a voice removal plugin. Written by Anders Carlsson. Basically it removes any sound in the center channel. Typically in a stero recording the instruments are at various locations, but not usually in the middle. With a soloist, the voice is usually centered. Any sound that's identical in the left and right channel is removed. It works pretty well, but not perfectly. 71.199.123.24 21:57, 27 July 2006 (UTC)

Return to (page)

Where can I find the code and MediaWiki template that allows someone to return to the last page he/she was viewing after logging in? -- Wikitravel Sapphire 04:54, 27 July 2006 (UTC)

Black screen in text mode

I have a very annoying problem. When I boot up the computer it doesn't show anything at all for a long time but then the Windows boots up and everything looks okay. But if I run a text mode aplication in fullscreen everything goes black again. It seems that my computer for some reason is unable to display anything in text mode. The problem appeared after the old power supply started to deteriorate, but it continues with the new power supply as well - maybe videocard or motherboard got damaged in some way. Did anyone had or heard of this problem? What is likely to be at fault?  Grue  08:50, 27 July 2006 (UTC)

It sounds like the video card lost the ability to display in VGA mode and is only doing SVGA. Assuming you have an average computer, a replacement video card isn't very expensive and easy to install. If you are like many gamers with video cards that cost more than the rest of the computer, then I'd just suffer with the loss of VGA. --Kainaw ^(talk) 14:47, 27 July 2006 (UTC)

Woth Playing NTSC disc in PAL compatible Player?

Guys!...Is it typically bad for the optical pickup in a DVD Player if an NTSC DVD movie is forced or tried to play in a PAL DVD Player or in a player that doesn't support NTSC format?..Will the laser pickup loose it's power eventually as a due of this?.Please Do Not mention the TV compatible format and the region code restrictions,since my question is all about the laser diode/circuitory response or health as a result of playing incompatible formats!... —The preceding unsigned comment was added by Balan rajan (talk • contribs) 10:58, July 27, 2006 (UTC).

If by 'optical pickup' you mean the laser which reads information off the DVD, no, certainly not - all the laser does is read information off the disk, it doesn't know anything about encoding, that's all handled by other pieces of electronics. The laser doesn't care what it's reading, of whether the rest of the player can make sense of it. — QuantumEleven 09:11, 27 July 2006 (UTC)

Oh fine.Thanks perhaps I too wondered this way...,but I've heard from many that when lasers are subjected to read some discs of either incompatible format or scratched one,the laser power gradually reduces because of excessive strain...Is it true so?..Or will playing the wrong compatible DVD or typical one make any electronic circuitry damage or some kinda firmware mess?..Because many times I've noticed that the ejection door has failed to eject at such occasions and the disc spin up never spins down until it's turned to off and back on...

Morever, it's just a laser diode and hence it has life time hours say 10,000hrs for instance.Now if it's subjected to much strain? won't its life time be shortened?...So I guess not many companies recommend to play scratched or damaged DVDs in their product and claims no warranty if hooked,is it so?..

It's a laser, not a human :) Components like lasers do not suffer any "strain" from reading damaged or incompatible disks. It sounds like your friends are anthropomorphising your DVD player a tad too much. The expected lifetime of a laser affected by such things like ambient temperature and humidity, how often it's dropped or kicked around and how often you stick a pen into the CD slot and poke around inside - reading damaged disks (unless they are so badly warped that, by spinning, they impact the read head) or incompatible disks has no effect on the expected lifetime of the laser. You can put your mind at ease. — QuantumEleven 13:28, 27 July 2006 (UTC)

However, while the laser will not be affected by bad disks, the firmware of the player can get confused, causing it to do some things with the mechanical parts which have some small possibility of causing strain to the hardware. For instance, some players fail to brake the spindle (which can even cause the disc to go flying if it is ejected while still spinning); some other players might move the pickup (where the laser is) back and forth a lot of times before giving up (trying to find a specific point at the disc and failing). Any firmware confusion, however, should be easily cleared with a reset. --cesarb 16:09, 27 July 2006 (UTC)

Is this question being asked in relationship to a Playstation 2? It is commonly held that the dvd readers in certain models are 'sensitive' to certain kinds of media and can actually fail prematurely due to long term use. This affected all types of discs on the early models, and on later models was mostly a problem for recordable media. In any event, it is the physical media causing the issue and not the way the data is encoded. --Jmeden2000 18:09, 27 July 2006 (UTC)

Free Video Converting

Where can I get a truly free video converter (i.e. no shareware or trial version) to convert video formats, specifically from .rmvb to .wmv and MPEG. Many thanks! --217.42.132.207 09:18, 27 July 2006 (UTC)

By the way did you try in Google Search?...I recommend you sure will get what you are looking for.You can by the way use any Video converter but what all you gonna need is the necessary codec which you can avail in many sites for free depending upon the codec type...they may or mayn't be for free...

In addition to google try videohelp.com, how to...convert link at the left. Weregerbil 10:53, 27 July 2006 (UTC)

Indeed. Keep searching on google. Search things like "freeware video converter" ".rmvb to .wmv freeware" "freeware file converter" etc. --Proficient 15:59, 27 July 2006 (UTC)

I don't know what the ".rmvb" format is, but MEncoder can convert almost anything under the sun. --Serie 23:24, 27 July 2006 (UTC)

DVD-R compatibility question

Hello, I was wondering if a DVD-R, once recorded, can be used in any computer DVD drive, or if it will only work on drives that are specfically labeled DVD-R or DVD±R. I've already checked the DVD-R and DVD+R pages, as well as others, and none of the pages answer this question.

Some more context for this question: I have a lot (about 3 GB worth) of vacation pictures, and I was hoping to share these with relatives and friends, some of whom aren't so computer-savvy and have no idea what DVD types their computers will take. I have an older drive that will burn DVD-R but not DVD+R.

Thanks for your help. --Tachikoma 12:33, 27 July 2006 (UTC)

It's a difficult question - a DVD writer (a drive labelled "DVD-R" or "DVD+R") can obviously read them. With DVD-read drives (ie drives that can only read but not write DVDs), it comes down to when they were built. Drives that were made after DVD-R and DVD+R were commonly introduced will read them, drives before them won't. For instance, I have a PC bought in 2000 which has a DVD-read drive which won't read DVD+R discs (which were introduced in 2002). However, I can't give you a more specific 'cut-off' date, I imagine it probably varies by manufacturer. Looking through a computer catalogue, I can find any number of DVD-read drives which will read DVD-R and DVD+R (from the detailed technical spec), even though it doesn't say that anywhere on the drive itself. My recommendation: burn your photos to a DVD-R (it was introduced in 1997 and is therefore more likely supported by older computers), and for the two people who have a computer built before about 1998 you can come up with a custom solution :) — QuantumEleven 13:17, 27 July 2006 (UTC)

I may have to resort to burning several CD-Rs instead. Thanks for your answer. --Tachikoma 14:35, 27 July 2006 (UTC)

File Tansfer Through Lotus Notes

I have to develop an application using lotus notes Now I need to tranfer this file using the lotus note code itself How do I do that?

Laptop spec

Hello all. I am buying a new laptop. I want a laptop because it's portable (duh), and I can play Civ 4 while sat on the toilet. Plus I'm getting cheap wireless broadband. But this is my question. What sort of spec should I be looking for? I don't want anything ridiculously powerful at a very high price; I want something that will run modern games happily, and will be fast when browsing the net, using Office, etc. And how good a graphics card would it need? Proto::type 15:32, 27 July 2006 (UTC)

A lot of people get Dell laptops and use the various discount coupons that can be found on the Internet. Perhaps you can take a look at these: http://www.dell.com/content/products/features.aspx/entnb_e1505?c=us&cs=19&l=en&s=dhs.

You should probably be looking for at least 1 GB RAM, and a dedicated GPU (probably 256 MB). A dual core laptop will probably be nice as well, since more and more games/software are taking advantage of the two cores. --Proficient 16:11, 27 July 2006 (UTC)

If you plan on using wireless, see what the capabilities of your wireless access point are and ensure you are taking full advantage of it. A fast access point will not speed up a slow wireless modem in your laptop. --Kainaw ^(talk) 17:27, 27 July 2006 (UTC)

Playing a game in the bathroom on a laptop can be difficult. If the game requires that the CD be in the computer, the CD can get dammaged (a laptop should be on a stable level surface when there is a CD in the drive). Cloning the CD and loading an image could solve that problem. Also the computer runs slower when not pluged in. But maybe you have a desk and a plug in your bathroom. That would be cool. Jon513 18:40, 27 July 2006 (UTC)

Another Firefox question (scrolling)

In IE, when you middle-click, you get a scroller that scrolls when you move the mouse. Firefox has it too, but when you use the arrow keys on the keyboard, it doesn't move. Is there an extension or perhaps some option in about:config to make it work with arror keys? Wizrdwarts (T|C|E) 23:19, 27 July 2006 (UTC)