[fdo-users] Spatial conversion

[Ytse]

I've tried using PROJ4 but there's something I dont' understand, if anyone is at ease with this project :

this command line works
proj -I -f "%.14f" +proj=lcc +lat_1=46.8 +lat_2=0 +lat_0=46.8 +lon_0=2.33722916666667 +x_0=600000.000 +y_0=2200000.000 +a=6378249.200 +b=6356515.000 +units=m -v

but this code won't work

        [DllImport("proj.dll")]
        static extern IntPtr pj_init(int argc, string[] args);
        [DllImport("proj.dll")]
        static extern string pj_free(IntPtr projPJ);
        [DllImport("proj.dll")]
        static extern UV pj_fwd(UV uv, IntPtr projPJ);
        static void Main(string[] args)
        {
            string[] NTF_Paris_France_II = new string[] { "proj=lcc", "lat_1=46.8", "lat_2=0", "lat_0=46.8", "lon_0=2.33722916666667", "x_0=600000.000", "y_0=2200000.000", "a=6378249.200", "b=6356515.000", "units=m" };            // from nad\esri
            IntPtr projPJ = pj_init(NTF_Paris_France_II.Length, NTF_Paris_France_II);
            UV lonlat = pj_fwd(new UV(663218.111631, 1795540.110104), projPJ);
            pj_free(projPJ);
            Console.WriteLine("Lon=" + lonlat.U + ",Lat=" + lonlat.V);
            Console.ReadLine();
        }
but I obtained U=V = +infinite, and using pj_inv I get some coords but they don't match the good ones from the command line

I've sent a mail to proj at lists.maptools.org but if anyone can help even though it's not directly related to FDO, thanks


----- Message d'origine ----
De : Dan Stoica <dan.stoica at autodesk.com>
À : Gavin Cramer <gavin.cramer at autodesk.com>; Ytse <bill_gfr at yahoo.fr>; fdo-users at lists.osgeo.org
Envoyé le : Lundi, 12 Février 2007, 17h42mn 44s
Objet : RE: [fdo-users] Spatial conversion


" ... but I haven't obtained anything else that "Default" in GetName() for my test files ?"

GetName() returns the name of the Spatial Context.
Look for GetCoordinateSystem() and GetCoordinateSystemWkt() for info pertaining the Coordinate System.

Dan.


-----Original Message-----
From: fdo-users-bounces at lists.osgeo.org [mailto:fdo-users-bounces at lists.osgeo.org] On Behalf Of Gavin Cramer
Sent: Monday, February 12, 2007 11:28 AM
To: Ytse; fdo-users at lists.osgeo.org
Subject: RE: [fdo-users] Spatial conversion

FDO does not itself support coordinate conversion.  What you will get from the Spatial Context is the name or definition of a coordinate system.  There are several ways to get do what you want...

1.  If you are using MapGuide, its API can do it.  The open-source version effectively results in the next approach...

2.  Use OGR directly.  Both this solution and #1 above will result in calls to PROJ.4 (http://www.remotesensing.org/proj/).

3. Spin your own solution, using whatever general solution (like PROJ.4) that you have available.  You can save time coding access to the FGF content by using a handy example class that sits in GeometryTest.cpp, in the FDO unit test.  Look for the GeometryConverter class.  You just have to fill in or override the ConvertPosition() methods to call whatever conversion package you choose.

I haven't worked much directly with the components for #1 or #2 above, so hopefully someone else will give more details if one of those fits your case.

Gavin


-----Original Message-----
From: fdo-users-bounces at lists.osgeo.org [mailto:fdo-users-bounces at lists.osgeo.org] On Behalf Of Ytse
Sent: Monday, February 12, 2007 9:38 AM
To: fdo-users at lists.osgeo.org
Subject: [fdo-users] Spatial conversion

Hi everyone, 

are there any ways to convert coordinates from one system to another using FDO ? 
(In my case that would be from LAMBERT IIe to WGS84)

By the way I know my files are in this system, but is it possible to detect it using FDO ? 
I thought I'd be able to do this by using using OSGeo.FDO.Commands.SpatialContext but I haven't obtained anything else that "Default" in GetName() for my test files ?

thank you


    

    
        
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