Re: Reversing a coordinate operation via proj api

On vendredi 13 décembre 2019 10:06:19 CET Nyall Dawson wrote:
> On Fri, 13 Dec 2019 at 09:55, Even Rouault <[email protected]> 
wrote:
> > Hi Nyall,
> > 
> > > If I have a proj string representing a coordinate operation, is there
> > > any existing proj c api to reverse this operation?
> > 
> > Do you mean, to get a PROJ string corresponding to the reverse operation ?
> 
> Yes. Or even if there was a method to take any given PROJ coordinate
> operation object which is already constructed and create a reversed
> clone of it.

Ah, a proj_coordoperation_create_inverse(PJ_CONTEXT*, PJ*) function should be 
easily doable as there's already the C++ counterpart as 
CoordinateOperation::inverse() (for a PROJ string, PROJ has already the logic 
internally to split & reconstruct)

That will not help you with dealing with released versions, but if it can make 
the future better, I can do that.

Even


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