New plotting documentation



James Amundson [23/07/04 10:12 -0500]:
> I have updated the plotting documentation. All of the changes are
> contained in the description of PLOT_OPTIONS, which is now quite long. I
> rewrote the entire description, including portions involving old
> options. I think the result is much more coherent than the old version. 
> 
> It would be useful to have someone else read through what I wrote to see
> if the documentation makes sense to someone other than the author.
> 
> --Jim
> 

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. 
	
  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."

I then tried to 
set_plot_option([transform_xy, maketransform(... same thing as
above)]);
and got the same error. 

I also tried to assign, say 
q:maketransform([x,y,z],[x+y,x-y,z]);
and then
set_plot_option([transform_xy, q]);
with the same error as a result.

The reason I tried this in the first place is that after reading
your description of TRANSFORM_XY, I was not sure how one was
supposed to use that particular option.

Hope this question can be of some use.

Milan



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