Hi Francois, On Fri, 15 Oct 2010 21:46:36 +0200 Francois Maltey <fmal...@nerim.fr> wrote:
> You wrote (I cut a lot) > > Yup, I see what you are talking about - e.g. > > > > if (x.is_equal(_ex1)) // log(1) -> 0 > > return _ex0; > > > > Although it might be nice to stay relatively close to Ginac and fix > > such things on the Sage level if that's not really bad. > > > > This is a bug in the log() function, and any other function which > > returns exact values like 0 or 1. We already work around most cases, > > see lines 720-722 and 736-761 of sage/symbolic/function.pyx. > > > I don't understand where and when these lines are used ? > I notice there are no name about usual functions (sin, cos, log, exp) > in this file > So I don't understand how this filter (from int(0) to integer(0)) can > be done. That file defines the basic behavior of symbolic functions in Sage. The class GinacFunction is the base class for functions provided by GiNaC/pynac. The wrapper classes for these functions inherit from this class, so they get the __call__() method, which is used when you call a function. So the command ln(1) actually goes through that __call__() method. Cheers, Burcin -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
