%ORTH Orthogonalisation of an affine mapping
%
%  V = ORTH(W)
%
%In case W is an affine mapping it is orthogonalised. Otherwise
%an error is generated. The output mapping V has no offset and has
%thereby a distance zero to the origin.
%
%SEE ALSO (<a href="http://37steps.com/prtools">PRTools Guide</a>) 
%MAPPINGS, AFFINE