[Proj] cs2cs vs. proj??

Gerald I. Evenden geraldi.evenden at gmail.com
Mon Feb 16 11:57:37 EST 2009

On Monday 16 February 2009 11:04:54 am Frank Warmerdam wrote:
> Gerald I. Evenden wrote:
> > A question has arisen in my mind as to what is the difference between the
> > programs cs2cs and proj?  What does one do that the other does not?
> >
> > On the surface the names would imply that one deals with transforming
> > data between datum systems, which may include projections as a
> > suboperation, and the other would deal with only cartographic
> > projections.
> Gerald,
> This is essentially the case, yes.  The cs2cs program uses the
> pj_transform() functions which includes support for datum shifts,
> prime meridian shifts and goes from one coordinate system to another.
> The proj program on the other hand is largely unchanged from the
> original, uses pj_fwd() and pj_inv() and does not support any
> of the extended capabilities of pj_transform().
> > Obviously, as I am painfully aware, this is not the case.
> I'm not sure why you think this is not the case.

I suspect that it is because some of the conversations are discussing the 
library as proj.

PS: the line in proj-4.4.9/man/man1/proj.1

       The geod program provides the ability to compute
       geodetic (Great Circle) computations.

should read "geodesic" and not geodetic.

The whole religious complexion of the modern world is due
to the absence from Jerusalem of a lunatic asylum.
-- Havelock Ellis (1859-1939) British psychologist

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