[Proj] PROJ 4.6.0 beta1 Release
Frank Warmerdam
warmerdam at pobox.com
Thu Nov 29 13:44:06 PST 2007
Folks,
There have been many complaints from folks about pj_datum_transform()
doing "ellipse to ellipse" datum shifts when no datum shift information
is available. I have come to the, belated, conclusion that the idea will
ill conceived on my part, and I have reversed my approach.
Now, if pj_datum_transform() (called pj_transform()) is called, and
either of the coordinate system lacks datum information it will apply no
datum shift at all. The lat/long coordinates will be taken from one
and applied on the other with alteration.
Datum shift information can be specified two ways, a +towgs84 parameter,
or a +nadgrids parameter. The +datum parameter is basically for named
aliases that expand to +ellps and either +nadgrids or +towgs84 parameters.
This is a major behavior change, and I'd appreciate folks giving some feedback
on the change. I have prepared a first beta release with this change,
designated 4.6.0 beta1.
This release also includes an upgrade to EPSG 6.14 and a few other relatively
minor bug fixes.
http://download.osgeo.org/proj/proj-4.6.0b1.tar.gz
http://download.osgeo.org/proj/proj-4.6.0b1.zip
Best regards,
--
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush | President OSGeo, http://osgeo.org
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