On Mon, May 4, 2009 at 12:02 PM, kcrisman <kcris...@gmail.com> wrote: > > In order to plot zeta for real input, I have to do the following: > def Zeta(x): > return RR(zeta(x)) > plot(Zeta,2,20) > > This is because > sage: zeta(2) > 1.64493406684823 > sage: type(zeta(2)) > <type 'sage.rings.complex_number.ComplexNumber'> > > which seems odd to me that pure real complex number won't coerce to > the real field, or to float (which is what plot wants).
This is a Python design decision. Note that in pure Python it is the same. Sage remains consistent with this Python design decision. sage: float(complex(1,0)) TypeError: can't convert complex to float; use abs(z) > Also annoying but less odd is that the error handling in plot doesn't > deal well with > > plot(Zeta,1,20) > > presumably because PariError is not one of the error types excepted at > e.g. asymptotes. That Zeta ever raises PariError might as well be considered a bug. (It's more a "nobody got to making things better" issue.) You might use some exception handling in your definition of Zeta. -- William > I guess the point of this is asking whether there is something obvious > I am missing here, and if not, whether this is a bug or just something > I have to deal with. Not that the real plot of zeta is so exciting to > look at! > > Thanks! > - kcrisman > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
