[postgis-users] Create a rotate() function?

[Bruce Rindahl]

>In the proj philosophy, things with go from lat/lon -> x/y is a  
>projection and from x/y to lat/lon is an invprojection, but that's  
>it.  An affine transform is a different beast.  I guess we do need to  
>complete the set of transformation functions, with a rotation(), and  
>then a full affine().  I like the idea of having scale(), translate 
>(), rotate() around, for those who (like me) do not necessarily think  
>in matrices about these issues.  But having an affine() as well would  
>be good for those sophisticates who want to do several things at once.

If a full affine is available then scale, translate and rotate become
SQL functions and we don't have to code them at all.  They simply call
affine with the appropriate parameters.

Bruce Rindahl