[Proj] PROJ 4.6.0 beta1 Release

Frank Warmerdam warmerdam at pobox.com
Thu Nov 29 16:44:06 EST 2007


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.


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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