[Proj] proj=undef ??

support.mn at elisanet.fi support.mn at elisanet.fi
Mon Jun 27 08:01:57 PDT 2011


Frank,

mayby there are 2 possibilities to give these pseudo
projections. Either:

proj=undef
units=degr

or directly:

proj=degr

----------

proj=undef
units=rad

or directly:

proj=rad

I am not sure what would be the exact difference? What
does the "units=...." statement exactly do?

Regarding to datum shifts this should not affect them
at all... they should continue to work as they always
have... the projection in this case is just very simple..
it does nothing at all just transfers the input to output
[the data is already earth angular forward or inverse].

BTW: I have somewhere seen

proj=wgs84

is that a legal proj.4 projection? and what does it
mean?

Janne.

-------------------------

Frank Warmerdam [warmerdam at pobox.com] kirjoitti: 
> On 11-06-25 01:42 PM, support.mn at elisanet.fi wrote:
> > Hello,
> >
> > to be exact, we needed pseudo projections
> > for degrees and radians:
> >
> > "proj=degr"
> 
> Janne,
> 
> I would think adding an angular units keyword would be a better
> approach to this though it is confusing since the user facing units
> have always been degrees and the API level units have always been
> radians.  I'm not really clear how this relates to applying datum
> shifts.
> 
> 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    | Geospatial Programmer for Rent
> 
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