[MetaCRS] Proj4js: Converting from EPSG:4326 -> EPSG:28193 fails

Christopher Schmidt crschmidt at metacarta.com
Tue Mar 24 16:26:38 EDT 2009


On Tue, Mar 24, 2009 at 01:22:15PM -0700, Hugues Wisniewski wrote:
> One solution would be the MapGuide API I think. SWIG is used on the C++ API to generate java APIs

Java is not Javascript; Javascript runs in a browser environment, rather
than on the server, which is what the OP is looking for. No library
other than proj4js (or its predecessors in Javascript land) does this at
this time.

-- Chris

> -----Original Message-----
> From: Christopher Schmidt [mailto:crschmidt at metacarta.com] 
> Sent: Tuesday, March 24, 2009 12:11 PM
> To: Hugues Wisniewski
> Cc: Josh Rosenthal; Mike Adair; metacrs at lists.osgeo.org
> Subject: Re: [MetaCRS] Proj4js: Converting from EPSG:4326 -> EPSG:28193 fails
> 
> On Tue, Mar 24, 2009 at 12:02:27PM -0700, Hugues Wisniewski wrote:
> > Hi,
> > 
> > I don't know if you'd be interested in this but CsMap supports this Cassini projection and the system 28193
> > You can access the CsMap API or if you have access to the MapGuide MgCoordinateSystem API that is a wrapper around CsMap you can do it too
> 
> Proj.4 does as well; but neither proj.4 nor CsMap are accessible in
> Javascript.
> 
> -- Chris
> 
> > Hugues
> > 
> > From: metacrs-bounces at lists.osgeo.org [mailto:metacrs-bounces at lists.osgeo.org] On Behalf Of Josh Rosenthal
> > Sent: Tuesday, March 24, 2009 9:45 AM
> > To: Mike Adair
> > Cc: metacrs at lists.osgeo.org
> > Subject: Re: [MetaCRS] Proj4js: Converting from EPSG:4326 -> EPSG:28193 fails
> > 
> > Hi Mike,
> > 
> > Thanks a lot.  I couldn't figure out if I was doing something wrong or...  In any case, you said 'yet'.  Is there a timeline as to when we could expect cassini projections to be supported, or do you have any other suggestions as to how to convert coordinates to/from that?  Curiously, it appears as though spatialreference.org<http://spatialreference.org> does support those reprojections, though I'm not sure what the back end is over there.
> > 
> > In any case, any advice would be welcome,
> > 
> > Thanks,
> > 
> > Josh
> > 2009/3/24 Mike Adair <madair at dmsolutions.ca<mailto:madair at dmsolutions.ca>>
> > Josh,
> > 
> > The cassini projection code ("proj=cass") hasn't been implemented in Proj4js yet.
> > 
> > Mike
> > 
> > 
> > Josh Rosenthal wrote:
> > Hi Folks,
> > 
> > I hope I'm sending this to the right list.  Apologies if not.
> > 
> > I'm hitting a bit of a problem with a proj4js conversion, and I'm hoping someone can help.  I'm trying to go from EPSG 4326 to 28193, and I'm just getting my original coordinates returned.  As per http://spatialreference.org/ref/epsg/28193/ , I have the proj4js definition for 28193 as:
> > Proj4js.defs["EPSG:28193"] = "+proj=cass +lat_0=31.73409694444445 +lon_0=35.21208055555556 +x_0=170251.555 +y_0=1126867.909 +a=6378300.789 +b=6356566.435 +towgs84=-275.722,94.7824,340.894,-8.001,-4.42,-11.821,1 +units=m +no_defs";
> > 
> > To demonstrate, I've modified the converter in the proj4js homepage to also have 28193 (Old Israel Grid/Palestine 1923) and 2039 (New Israel Grid).  You can see the demo here: http://arkeotech.googlepages.com/Proj4js.htm
> > Converting the coordinates 35,31 from 4326 to 2039 works fine, but from 4326 to 28193 just returns 35,31.  Looking at the spatial reference page for 28193, you can use the viewer to get an approximation for those coordinates... it should be somewhere roughly around 149353, 1046172
> > 
> > Any thoughts?
> > 
> > Thanks,
> > 
> > Josh
> > 
> > 
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> > 
> > --
> >  Michael Adair
> >  Senior Software Architect
> >  DM Solutions Group Inc.
> > 
> >  Office: (613) 565-5056 x26
> >  madair at dmsolutions.ca<mailto:madair at dmsolutions.ca>
> >  http://www.dmsolutions.ca
> >  http://research.dmsolutions.ca
> > 
> > 
> 
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> 
> 
> -- 
> Christopher Schmidt
> MetaCarta

-- 
Christopher Schmidt
MetaCarta


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