On Fri, 2004-07-23 at 13:43, Milan Lukic wrote:
> It looks good! I do have a suggestion, and a question though.
>
> SUGGESTION: I think it would be very helpful if that long
> description of plot options could be illustrated by a few complete
> examples, including something very basic and something more
> complex.
A fine suggestion. There are many examples on
<http://maxima.sourceforge.net/maxgraphtmp/>;. I will copy a few into the
documentation.
> QUESTION: I am having trouble with the TRANSFORM_XY plot option.
>
> > TRANSFORM_XY allows transformations to be applied to
> > three-dimensional plots.
> > [TRANSFORM_XY, FALSE]
> > The default TRANSFORM_XY is FALSE. If it is not FALSE, it should be
> > the output of
> > make_transform([x,y,z], [f1(x,y,z),f2(x,y,z),f3(x,y,z)])
> > The POLAR_XY transformation is built in. It gives the same
> > transformation as
> > make_transform([r,th,z],[r*cos(th),r*sin(th),z])
> >
>
> I tried (on Maxima 5.9.0)
> plot3d(x^2+y^2,[x,-2,2],[y,-2,2],[transform_xy,
> maketransform([x,y,z], [x+y,x-y,z])]);
> Got the error:
> "FALSE evaluates to ERREXP1
> Improper name or value in functional position."
OK. You have a bug and the documentation has a bug. The score is even.
You have "maketransform" where you should have "make_transform". The
documentation says make_transform([x,y,z],
[f1(x,y,z),f2(x,y,z),f3(x,y,z)]), but it should say
make_transform([x,y,z],f1(x,y,z),f2(x,y,z),f3(x,y,z)). I'll fix the
documentation. It would be nice if Maxima gave you a more helpful error
message, but I'm afraid that won't get done right away.
I also see that there is no documentation for the function
make_transform itself. That's one more bug for the documentation, which
changes the score in your favor. It looks like you win!
Thanks for the feedback.
--Jim