Comments on: PHP GIS Functions http://www.derivante.com/2009/04/14/php-gis-functions/ to obtain or receive from a source Sat, 30 Jul 2011 08:51:15 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Arun http://www.derivante.com/2009/04/14/php-gis-functions/comment-page-1/#comment-411 Arun Tue, 16 Feb 2010 16:22:26 +0000 http://www.derivante.com/?p=313#comment-411 1) True. I agree. My latlongs are very close http://txtb.in/djf results: your centroid: 12.982224693774, 77.624733038687 mean centroid: 12.982286543056, 77.624984548135 I haven't tested this manually yet. But I am supposed to get a latlong a bit northeast. I didn't get enough time to test it with other latlong sets. Will do it. 1) True. I agree. My latlongs are very close http://txtb.in/djf
results: your centroid:
12.982224693774, 77.624733038687
mean centroid:
12.982286543056, 77.624984548135

I haven’t tested this manually yet. But I am supposed to get a latlong a bit northeast.

I didn’t get enough time to test it with other latlong sets. Will do it.

]]> By: Clay vanSchalkwijk http://www.derivante.com/2009/04/14/php-gis-functions/comment-page-1/#comment-410 Clay vanSchalkwijk Tue, 16 Feb 2010 15:47:02 +0000 http://www.derivante.com/?p=313#comment-410 1) I'm using a flat-earth model for performance and simplicity in the example above, which for the majority of calculations will suffice. If you need to do long distance calculations, you will need to switch over great-circle distance calculation. 2) Can you give me the example of this you are working with so I can try to debug the problem. 1) I’m using a flat-earth model for performance and simplicity in the example above, which for the majority of calculations will suffice. If you need to do long distance calculations, you will need to switch over great-circle distance calculation.

2) Can you give me the example of this you are working with so I can try to debug the problem.

]]> By: Arun http://www.derivante.com/2009/04/14/php-gis-functions/comment-page-1/#comment-409 Arun Tue, 16 Feb 2010 13:51:10 +0000 http://www.derivante.com/?p=313#comment-409 Good. But two problems: 1) you don't seem to consider the curvature of the earth's surface in to consideration. 2) in some cases, the centroid calculation is erroneous compared to a normal mean of the lat longs calculated separately. Or am I missing something completely? Good. But two problems:
1) you don’t seem to consider the curvature of the earth’s surface in to consideration.
2) in some cases, the centroid calculation is erroneous compared to a normal mean of the lat longs calculated separately.

Or am I missing something completely?

]]> By: Clay vanSchalkwijk http://www.derivante.com/2009/04/14/php-gis-functions/comment-page-1/#comment-344 Clay vanSchalkwijk Thu, 01 Oct 2009 14:25:59 +0000 http://www.derivante.com/?p=313#comment-344 $poly[] = array('0','5'); $poly[] = array('0','0'); $poly[] = array('5','0'); $poly[] = array('5','5'); if(pnpoly($poly,'1','1')) echo "1,1 is inside the polygon\n"; if(!pnpoly($poly,'1','6')) echo "1,6 is not inside the polygon\n"; $poly[] = array(’0′,’5′);
$poly[] = array(’0′,’0′);
$poly[] = array(’5′,’0′);
$poly[] = array(’5′,’5′);

if(pnpoly($poly,’1′,’1′))
echo “1,1 is inside the polygon\n”;

if(!pnpoly($poly,’1′,’6′))
echo “1,6 is not inside the polygon\n”;

]]> By: Anton http://www.derivante.com/2009/04/14/php-gis-functions/comment-page-1/#comment-343 Anton Thu, 01 Oct 2009 07:46:32 +0000 http://www.derivante.com/?p=313#comment-343 Hey there, thanks for the tools. I just have one question: can you provide a simple doc for your pnpoly() function, at least expected input data formats? Hey there, thanks for the tools. I just have one question: can you provide a simple doc for your pnpoly() function, at least expected input data formats?

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