Several issues about plotting follow.
In bug 552724 there is an example plot:
plot2d([5-x^2,x+3],[x,-2,1]);
With both openmath, the range of y is limited to -3 to +3 by the plot
options. I think this is a bug. We shouldn't limit the y range unless
specifically told to.
If I specify
plot2d([5-x^2],[x,-2,1],[y,-5,5])
this produces the desired openmath plot. However, if I want to use
gnuplot, the command
plot2d([5-x^2],[x,-2,1],[y,-5,5,plot_format,gnuplot])
produces an error because maxima wants just 2 items after y. I think
this is a bug. Making plot_format come first fixes this. I think we
should really specify the y option as y,[-5,5] instead of y,-5,5.
Then we get a uniform specification of the option name followed by
exactly one value of either the value or a list of values.
Also, if you use gnuplot, no plot is actually produced. I think the
reason is that what maxima writes out includes lines like
move x y
where x and y are numbers. These aren't valid gnuplot values, so I
think gnuplot just gives up. I have a hack to not print these lines,
and a plot is produced, but I'm not sure that is the right thing. I
don't understand why there are those move lines at all. (A left over
from PS plotting?)
Finally, it's impossible for the average person to figure out how to
use plot2d because describe just says:
- Function: PLOT2D (expr,range,...,options,..)
We need a little bit more here. :-) I'll try to cook up some docs for
this.
I haven't filed any of these a bugs, but if you want me to, I can. I
was planning on fixing these soon.
Ray