How compatible does it have to be?

[Daniel]

If I write a new function for a package, how comatible does it have to be with matlab?

For example, is the following difference considered a "bug"?

In matlab: 

        >> T=maketform('affine',[.5 0 0; .5 2 0; 0 0 1]);

        tformfwd([10 20],T)

        ans =

            15    40  

        >> tformfwd(T,[10 20])

        ans =

            15    40  

In octave: 

        octave:13> T=maketform('affine',[.5 0 0;.5 2 0;0 0 1]);              

        octave:14> tformfwd([10 20],T)                                       

        error: tformfwd: expect a transform structure as first argument 

Daniel