[Proj] Datum shift not working

[Even Rouault]

Paul,

as far as I know, the proj utility doesn't do datum shifts. You should rather 
use cs2cs (and as per 
http://trac.osgeo.org/proj/wiki/FAQ#WhydoIgetdifferentresultswith4.5.0and4.6.0, 
"PROJ.4 will now only apply a datum shift if both the source and destination 
coordinate system have valid datum shift information") :

$ cs2cs +proj=longlat +ellps=clrk80 +towgs84=0,0,0 +no_defs +to +proj=utm 
+zone=40 +ellps=clrk80 
+towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m 
+no_defs -f "%.6f"
59.28632619 24.27334106
731801.730465	2685882.517256 82.812593

$ cs2cs +proj=longlat +ellps=clrk80 +towgs84=0,0,0 +no_defs +to +proj=utm 
+zone=40 +ellps=clrk80 +units=m +no_defs -f "%.6f"
59.28632619 24.27334106
732098.167370	2686171.824604 0.000000

Even


Le samedi 30 août 2014 10:26:28, Paul Boettinger a écrit :
> Hello,
> i want to do a transformation with the EPSG Code 3440
> In my epsg file 3440 references the following parameters:
> +proj=utm +zone=40 +ellps=clrk80
> +towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m
> +no_defs
> 
> Executing proj 4.8.0_0 from the MacPorts Repository on OSX 10.9.4 makes no
> differences using the transformation with or without the datum shift. Any
> help welcome,
> 
> Paul
> 
> proj +proj=utm +zone=40 +ellps=clrk80
> +towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m
> +no_defs -f "%.6f" 59.28632619 24.27334106
> 732098.167370	2686171.824604
> 
> proj +proj=utm +zone=40 +ellps=clrk80 +units=m +no_defs -f "%.6f"
> 59.28632619 24.27334106
> 732098.167370	2686171.824604
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