Esempio
> S3d:=(sx,sy,sz)->matrix(4,4,[[sx,0,0,0],[0,sy,0,0],[0,0,sz,0],[0,0,0,1]]):
> trasforma([[x,y,z]],S3d(2,3,4));
>
![matrix([[2*x, 3*y, 4*z]])](images/geo592.gif){kind=small}