Hi, Le vendredi 1 mai 2015 17:23:55 UTC+2, Nils Bruin a écrit : > > On Friday, May 1, 2015 at 2:00:11 AM UTC-7, Eric Gourgoulhon wrote: > > >> Thanks for your answer. There is no predefined 'H' function in Sage, so >> do you mean a nameclash with a predefined function 'H' in Pynac ? Which >> function is it ? It seems to be (x,y) |--> - x ln(1-xy), but I don't see >> why this function is special and would deserve a predefined name. >> > > Most probably these (from > http://www.ginac.de/tutorial/#Built_002din-functions ): > > G(a, y)multiple polylogarithm G(a, s, y)multiple polylogarithm with > explicit signs for the imaginary parts S(n, p, x)Nielsen’s generalized > polylogarithm H(m, x)harmonic polylogarithm >
Thanks for your answer and the link! This is clearly the source of the problem. > This is clearly a problem in sage: we're not exposing these polylogs under > those names at all, and even for "sin" we do seem to support having new, > symbolic, user functions with that name (which will collide as soon as you > step into libmaxima or anything else that has to communicate function > identifiers by names in a flat namespace). The fact that we don't in > pickling is clearly a problem. > A workaround until something better could be to modify Sage's function(s, *args, **kwds) to generate an error (e.g. "this name is reserved") as soon as - s = 'sin' or any predefined Sage function - s='G' and len(args)=2 or 3 - s='H' and len(args)=2 - s='S' and len(args)=3 etc. But this might be tedious, given the large number of functions in Sage... Eric. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
