Projection Error

Topics: User Forum
Jul 9, 2008 at 8:30 PM
I am using the transform function and the results are not correct.  Here is a sample point: POINT (3156176 1638997).  I am trying to transform from epsg 2232 to 26913.  The result should be POINT( 504648.984, 4381868.760).  Instead I get POINT(615276.219443469 4824918.04197203).  It is suspiciously close to being off by the false easting and a factor of the false northing.  I get the correct result if I use proj net through sharpmap.  I set up a project using the same dlls (Sharpmap.CoordinateSystems, NTS, GeoAPI) as MsSqlSpatial uses and I got the same bad result.  Is there something I am doing wrong? 

I also tried John_Diss's new code for v2.  I noticed that it uses projnet.  Unfortunately the transform function does not seem to be implemented yet. It looks like the get function needs to be defined in global.cs.  Could you tell me how to define that?  Thanks

Jul 10, 2008 at 9:10 AM
Hi Joel, sorry i missed you on the irc, i had left my computer on when i went home.. currently there are outstanding issues in projnet v2 which is used by the v2 version of mssqlspatial so it isn't plumbed in yet. I'll let you know when it is ready.. .cheers jd
Jul 13, 2008 at 5:00 PM
Edited Jul 13, 2008 at 5:01 PM

Hi Joel, I have created a branch 1.7.x (following the NTS version number on which it is based) this has the most recent sources for GeoAPI 1.x, NTS 1.7.x, ProjNet 1.x.
It requires Unsafe deployment  
You may have issues if you try and install it into the same database server as a v2 version. These are due to the way the assemblies/assymetric keys/logins  are registered - beware.

Time constraints mean it is not thoroughly tested....
But the good news is the transform, as detailed above, passes..

cheers jd