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

Tue Mar 24 16:41:07 EDT 2009

Chris is right.  I'm trying to stick to the browser environment for this.
 Since I've basically requested that if anyone has the know-how and the free
time, and the gratuitous goodwill, they convert cass for proj4js, I'll
sketch out the use case as well (ie: why its more than just one wacky
unknown on a listserv).
I'm working on this in response to a query from a friend of mine in Israel.
 In Israel, many of the current maps list both New Israeli Grid (EPSG:2039)
and Old Israeli Grid (EPSG:28139, transformed with y - 1,000,000), but most
of the older records (before the mid 90s) only have OIG. There are also many
coordinates in lat/lon (4326) courtesy of the everpresent consumer GPS
units.  I'd basically been planning to build a little webapp which would
take multiple lines of comma delimited coordinates in one projection, and
convert them to another, with output available in html, csv, and as an excel
spreadsheet.  Easy to build, with an eye towards being easy and
straightforward to use.  Unfortunately, my programming skills get shakier
outside of a javascript environment, and in any case, it wouldn't work as a
publically accessible webapp.

Chris, you mentioned proj4js's js predecessors.  Do any of them handle the
cass projections?  I'm only familiar with proj4js.

Thanks,

Josh

On Tue, Mar 24, 2009 at 4:26 PM, Christopher Schmidt <
crschmidt at metacarta.com> wrote:

> 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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> > > http://lists.osgeo.org/mailman/listinfo/metacrs
> > >
> > >
> > > --
> > >  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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> > > http://lists.osgeo.org/mailman/listinfo/metacrs
> >
> >
> > --
> > Christopher Schmidt
> > MetaCarta
>
> --
> Christopher Schmidt
> MetaCarta
>
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