On Thu, Aug 21, 2008 at 10:58 AM, Mike Witt <[EMAIL PROTECTED]> wrote: > > This is an attempt to ask my previous question more clearly :-) > > 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 > > But I'm not sure. I notice that: > > sage: type(imag(f(x,1))) > <class 'sage.calculus.calculus.SymbolicArithmetic'> > > and: > > sage: type(imag(f(x,0))) > <class 'sage.calculus.calculus.SymbolicConstant'> > > So, perhaps I could use this test (at least in this particular case) to > avoid calling parametric_plot and simply draw a line instead. But > I wonder if there is a more general strategy. For example, a single > test that will tell if a function if going to evaluate to any kind > of "constant" that plot or parametric_plot will have a problem with? > > I'm trying to be as clear as I can about this. I'm very new to Sage, > and I realize that I could be missing something obvious. >
Just out of curiosity, do you know Python? If not, you might *greatly* benefit from learning Python, which is a pretty easy thing to do -- it takes a few hours to get up to speed with the basics and there are many good free resources online. William --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
