Module:MapClip/testcases: Difference between revisions
Setting a feature at two gridlines. Fixing the inaccuracy requires first getting the feature to align perfectly with the grid - then deciding on some method, however ad hoc, to calibrate image clip. |
Zooming in for the final touches ... turns out there are MULTIPLE inaccuracies here, because the feature isn't lining up with the grid! |
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{{#invoke:MapClip|map|regionwestedge=-85|regioneastedge=-80|regionnorthedge=26|regionsouthedge=22|feature1=Key West|feature1lat=24°33′33″N|feature1long=81°47′03″W|feature2long=-82|feature2lat=24|grid=red}} |
{{#invoke:MapClip|map|regionwestedge=-85|regioneastedge=-80|regionnorthedge=26|regionsouthedge=22|feature1=Key West|feature1lat=24°33′33″N|feature1long=81°47′03″W|feature2long=-82|feature2lat=24|grid=red}} |
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{{#invoke:MapClip|map|regionwestedge=-82|regioneastedge=-81|regionnorthedge=25|regionsouthedge=24|feature1=Key West|feature1lat=24°33′33″N|feature1long=81°47′03″W|grid=red}} |
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This error in Key West seems to be more than a bug: looking at the original image in GIMP, the island occupies x=174,175;y=1445,1446. Added to 1991,1990 I get 2164,1445 (+1,+1). From the article the position is 81.7841666666 W 24.55916666 N. If pixel per degree longitude = 1991*4/360 then 21.12222222 should be the ratio. But 180-81.784166666 =98.215833333 E which times 21.12222222 gets me 2074, not 2164! It may be tricky to get it right. |
This error in Key West seems to be more than a bug: looking at the original image in GIMP, the island occupies x=174,175;y=1445,1446. Added to 1991,1990 I get 2164,1445 (+1,+1). From the article the position is 81.7841666666 W 24.55916666 N. If pixel per degree longitude = 1991*4/360 then 21.12222222 should be the ratio. But 180-81.784166666 =98.215833333 E which times 21.12222222 gets me 2074, not 2164! It may be tricky to get it right. |
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Revision as of 13:08, 15 April 2013
Apparently there's some inaccuracy in how the map coordinates are assigned in the first place!!!
<div style="position:relative;overflow:hidden;width:280px;height:198px;"><div style="position:absolute;overflow:visible;top:-117px;left:-4px;clip:rect(132px,264px,308px,44px);">[[File:Topographic30deg_N30W60.png|264px|]]</div><div style="position:absolute;overflow:visible;top:147px;left:-4px;clip:rect(-132px,264px,44px,44px);">[[File:Topographic30deg_N0W60.png|264px|]]</div><div style="position:absolute;overflow:visible;border:solid red;border-width:0 1px 0 0;top:15px;width:0px;height:176px;left:84px;"></div><div style="position:absolute;top:-2px;width:40px;font-size:75%;color:red;text-align:right;left:54px;">80W</div><div style="position:absolute;overflow:visible;border:solid red;border-width:0 1px 0 0;top:15px;width:0px;height:176px;left:172px;"></div><div style="position:absolute;top:-2px;width:40px;font-size:75%;color:red;text-align:right;left:142px;">70W</div><div style="position:absolute;overflow:visible;border:solid red;border-width:0 1px 0 0;top:15px;width:0px;height:176px;left:260px;"></div><div style="position:absolute;top:-2px;width:40px;font-size:75%;color:red;text-align:right;left:230px;">60W</div><div style="position:absolute;overflow:visible;border:solid red;border-width:0 0 1px 0;top:59px;height:0px;width:220px;left:40px;"></div><div style="position:absolute;top:50px;width:40px;font-size:75%;color:red;text-align:right;left:0px;">40N</div><div style="position:absolute;overflow:visible;border:solid red;border-width:0 0 1px 0;top:147px;height:0px;width:220px;left:40px;"></div><div style="position:absolute;top:138px;width:40px;font-size:75%;color:red;text-align:right;left:0px;">30N</div><div style="position:absolute;overflow:visible;height:15px;width:15px;top:41px;left:130px;">[[File:Full Star Yellow.svg|15px]]</div></div>
This error in Key West seems to be more than a bug: looking at the original image in GIMP, the island occupies x=174,175;y=1445,1446. Added to 1991,1990 I get 2164,1445 (+1,+1). From the article the position is 81.7841666666 W 24.55916666 N. If pixel per degree longitude = 1991*4/360 then 21.12222222 should be the ratio. But 180-81.784166666 =98.215833333 E which times 21.12222222 gets me 2074, not 2164! It may be tricky to get it right.
