[PROJ] Transformation for local grid

[Pierre Chaponniere]

Hi Even & all,

thanks a lot, the change does the trick and I am able to consider my +zoff
argument.

A subsequent issue has emerged since then...

I want to add a cs2cs transform in my pipeline where I already use cct.
Appears there is a conflict in doing so.
What I would like to do is to pipe the following

cct +proj=pipeline
+step +proj=cs2cs EPSG:4978 EPSG:4326
+step +proj=tmerc +lat_0=-1.90355333888889 +lon_0=115.900912891667
+y_0=538.374 +x_0=5200.27 +ellps=GRS80
+step +proj=affine +xoff=-5225.30897756133 +yoff=830.070127940344
+step +proj=affine +s21=-0.0072010369955164367159
+s12=0.0072010369955164367159
+step +proj=affine +xoff=5225.30897756133 +yoff=-830.070127940344
+step +proj=affine +xoff=-9.85881089465147 +yoff=-0.172038726321603
+zoff=-18.541

But my issue is that cct does not seem to 'like' my cs2cs argument - I get
a bad transformation argument error
How could I specify this transformation inside the pipeline ? I would like
as much as possible not to use 2 pipes, just a single one.
The other issue is that cct seems to consider the order long/lat while
cs2cs accepts lat/long - is there a way to modify the formating or I need
to use the -c argument to sepcify the field order ?

Thanks again for your help on this subject !
Hopefully this will be my last request.

Best regards,

Pierre C


Le lun. 10 févr. 2020 à 12:45, Even Rouault <even.rouault at spatialys.com> a
écrit :

> On lundi 10 février 2020 12:07:31 CET Pierre Chaponniere wrote:
> > Dear all,
> >
> > thanks heaps to Jochem and Even, this is great ! What a reactivity !
> > I managed to run my translation, rotation and back - all went well.
> >
> > I thought the easiest would have been the z but somehow proj does not
> > recognize my +zoff argument for an affine transformation.
> >
> > For example in my below proj command, the +zoff is ignored...Have you
> > encountered this before?
>
> "proj" is the ancient way of transforming coordinates, and as its name
> suggests (or not), it is only meant at dealing with plain cartographic
> projections, and 2D coords only, and generally not pipeline strings. That
> it
> works a bit for you is a bit by accident. It copies blindly any numeric or
> non-numeric values after the first 2 ones.
>
> Just replace "proj" by "cct" and you'll get the expected result.
>
> --
> Spatialys - Geospatial professional services
> http://www.spatialys.com
>
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