[postgis-users] Projection help (please, now thankyou!)

[Chapman, Martin]

Brent,

You could also make a UDF (user defined function) in PostgreSQL and put the code in there.  Then you could call that function using sql (like you call PostGIS functions ie. intersects(), overlaps()...), passing it the .prj file path or contents, do the conversion in the function, and then return the proj4 string.  Then it could be integrated with the rest of your sql code.  Although, you might want to check and make sure that function isn't there already...I don't know PostGIS that well. :)

Martin


-----Original Message-----
From:	Brent Wood [mailto:pcreso at pcreso.com]
Sent:	Tue 10/26/2004 8:44 PM
To:	PostGIS Users Discussion
Cc:	
Subject:	RE: [postgis-users] Projection help (please, now thankyou!)

Arrgghh... Now I have to learn C++!!!!

(actually I just got someone here to do it for me :-)

So my first play with C++, with a bit of help, & it works perfectly,

I just cat the prj file at the program to get the proj4 equivalent.

absolutely wunnerful....

Much appreciated. (& better support than I tend to get for commercial
packages!!)


Cheers

   Brent


--- "Chapman, Martin" <MChapman at sanz.com> wrote:

> Brent,
> 
> #include "ogrsf_frmts.h"
> #include "gdal_priv.h"
> 
> char* pszWks = "the text from the .prj file goes here";
> OGRSpatialReference spatialReference(pszWks);
> OGRErr err = spatialReference.morphToESRI(); // needed if the using an
> esri .prj file
> if (err != OGRERR_NONE) throw (char*) CPLGetLastErrorMsg();
> 
> char* pszProj4 = NULL;
> spatialReference.exportToProj4(&pszProj4);
> 
> -- there you go
> -- p.s I think the pszProj4 variable should be freed with
> CPLFree(pszProj4); -- not sure though, see the on-line docs for that
> 
> Martin
> 
> -----Original Message-----
> From: Brent Wood [mailto:pcreso at pcreso.com] 
> Sent: Tuesday, October 26, 2004 5:05 PM
> To: postgis-users at postgis.refractions.net
> Subject: [postgis-users] Projection help (please)
> 
> 
> 
> I have been given a Mapinfo binary map with CCAMLR data around
> Antarctica.
> 
> ogr2ogr turned it into a shapefile which is more useful I want to import
> this into a PostGIS table, but need to sort out the projection details
> to overlay it with other data in the database.
> 
> The shapefile version includes a .prj file, which I'm assuming will have
> the necessary info to locate or create the appropriate entry in the
> spatial_ref_sys table.
> 
> The contents of this file are below, can anyone help me translate this
> into a proj4text string?
> 
> 
> Thanks,
> 
>    Brent Wood
> 
> 
> more CCAMLR/Subareas_new_2003.prj
> PROJCS["unnamed",GEOGCS["unnamed",DATUM["North_American_Datum_1927",SPHE
> ROID["C
> larke
> 1866",6378206.4,294.9786982],TOWGS84[-8,160,176,-0,-0,-0,0]],PRIMEM["Gre
> e
> nwich",0],UNIT["degree",0.0174532925199433]],PROJECTION["Azimuthal_Equid
> istant"
> ],PARAMETER["latitude_of_center",-90],PARAMETER["longitude_of_center",0]
> ,PARAME
> TER["false_easting",0],PARAMETER["false_northing",0],UNIT["Meter",1.0]]
> 
> _______________________________________________
> postgis-users mailing list postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
> 


_______________________________________________
postgis-users mailing list
postgis-users at postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-users