On 08/21/2008 06:55:48 PM, Joel B. Mohler wrote: > > On Thursday 21 August 2008 01:58:23 pm Mike Witt wrote: > > I'm looking for a work-around for the situation where I would normally > > call parametric_plot (or plot, for that matter) with a function, and in > > some particular case that function turns out to evaluate to a constant. > > > > For example: > > > > sage: def f(a,b): return e^(a+b*I) > > ....: > > sage: parametric_plot([real(f(x,1)),imag(f(x,1))], -pi, pi) > > > > Works as expected > > > > sage: parametric_plot([real(f(x,-1)),imag(f(x,-1))], -pi, pi) > > > > Works as expected > > > > sage: parametric_plot([real(f(x,0)),imag(f(x,0))], -pi, pi) > > > > Gives a page full of errors, which I interpret to mean that there > > was a problem plotting because imag(f(x,0)) evaluates to a constant. > > > > I believe that this is the same issue described in: > > > > http://trac.sagemath.org/sage_trac/ticket/2410 > > I'm the person that entered the trac ticket and the point of that trac ticket > is precisely the (mis-)functionality you are describing. I'm truly > mystified by the other responses in this thread. To me, this is an obvious > bug... > > -- > Joel
Thanks Joel. I was beginning to wonder if I was nuts. Just to summarize what I've found out so far. The work-arounds suggested by David Joyner, Mike Hansen, and Carl Witty all work under certain assumptions, but none of the three provides a completely general fix as far as I can see. Using a combination of the techniques I am able to do what I want. But I am for whatever it's worth I'd certainly like to add my vote that tickets #2409 and #2410 should get attention. This issue with parametric_plot is certainly *very* confusing to a newcomer. -Mike --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---