[OpenLayers-Users] Change datum of apoint

[jkm]

Ok..

I already had the proj4js, but I was trying to transform to 4230, and the
result was not what I expected.
Now i'm using the 4668 and it seems to be ok!

Thanks a lot!

2011/2/11 Andreas Hocevar <ahocevar at opengeo.org>

> Hi,
>
> if you want to do this on the client, you will need proj4js (
> http://proj4js.org). To use it, add the following to your html page:
>
> <script type="text/javascript" src="
> http://proj4js.org/lib/proj4js-compressed.js></script>
> <script type="text/javascript">
> Proj4js.defs["EPSG:4230"] = "+proj=longlat +ellps=intl +no_defs";
> Proj4js.defs["EPSG:4668"] = "+proj=longlat +ellps=intl
> +towgs84=-86,-98,-119,0,0,0,0 +no_defs";
> </script>
>
> The EPSG code for ED50 is EPSG:4230, and for ED79 it is EPSG:4668. As you
> can see in the above definition, you won't have much luck with ED50, because
> the EPSG database does not have transformation parameters. For ED79,
> however, we can at least do a 3-parameter transformation.
>
> Now to convert a point from EPSG:900913 to ED79, you would do exactly as if
> you'd convert to WGS84, but use "EPSG:4668" instead of "EPSG:4326" as EPSG
> code.
>
> Note that you can find all available EPSG codes at
> http://spatialreference.org/.
>
> Regards,
> Andreas.
>
> On Feb 11, 2011, at 13:00 , jkm wrote:
>
> > Hi,
> >
> > I would like to know if is there any way to change the datum of a point..
> >
> > I'm working with a google maps base layer, and it returns the coordinates
> in EPSG:900913 and I transform them to WGS84. But what I would like, is to
> get lat/lon, in european79 or european50.
> >
> > I've seen in proj4js that there is a datum_transform function.. But it
> doesn't seem to transform the coordinates' datum..
> >
> > I'm in the right way? or what is supposed to do in that case?
> >
> > Thanks!
> >
> >
> > _______________________________________________
> > Users mailing list
> > Users at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/openlayers-users
>
>
>
> --
> Andreas Hocevar
> OpenGeo - http://opengeo.org/
> Expert service straight from the developers.
>
>
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