Changes between Initial Version and Version 4 of Ticket #6251
- Timestamp:
- Dec 10, 2015, 1:33:27 AM (8 years ago)
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Ticket #6251 – Description
initial v4 1 1 When computing distances between all points of a raster and a given pixel (the center of a city in a monocentric city model) using gdal_proximity.py, I obtained wrong distances. The error is not big, but not very small either, something like 5 or 10% (500-900m for 10km), depends on the CRS I used (I tried another one because I thought it was CRS-related) and is bigger in a North-South direction than East-West. 2 2 3 I saw the error when I computed the distance in another way (euclidian distance using the projected coordinates). I am confident that this euclidian distance is right because I compared it to the one given by an online national GIS system (http://www.geoportail.gouv.fr -- I was working on a French city), and the distances I measured w here in good agreement (and it worked for both CRSs I tried).3 I saw the error when I computed the distance in another way (euclidian distance using the projected coordinates). I am confident that this euclidian distance is right because I compared it to the one given by an online national GIS system (http://www.geoportail.gouv.fr -- I was working on a French city), and the distances I measured were in good agreement (and it worked for both CRSs I tried). 4 4 5 5 So I will just stop using gdal_proximity, also because I don't really need it in this project, but I wanted to mention the error -- I hope that this is the right place to do so.