AstSkyFrame *skyframe; AstSpecFrame *specframe; AstCmpFrame *cmpframe; ... skyframe = astSkyFrame( "" ); specframe = astSpecFrame( "" ); cmpframe = astCmpFrame( skyframe, specframe, "" );
If it was desired to make RA and Dec correspond to axes 1 and 3, with axis 2 being the spectral axis, then the axes of the CmpFrame created above would need to be permuted as follows:
int perm[ 3 ]; ... perm[ 0 ] = 0; perm[ 1 ] = 2; perm[ 2 ] = 1; astPermAxes( cmpframe, perm );
AST A Library for Handling World Coordinate Systems in Astronomy