In connection with some numerical simulations I am running, I need to calculate multiple polylogarithms to high precision ( 20 digits or more). I know that there exists functions in the Ginac library that can handle this, but I would rather work in python, hence I was wondering whether similar functionality exist here. If so how do I acces it (have been looking around in the documentation, but haven't found any mention of multiple polylogs). Any help would be most welcome. Thanks!
asked Sep 30 '10torben
21 ● 2
The code for numeric evaluation of polylogarithms in GiNaC calls the CLN library directly for speed. While removing the dependency on CLN, these functions were commented out. No one has tried to get them working within pynac since.
Looking at the relevant part of the code, which
I opened a ticket on the Sage issue tracker (#10050) to expose the polylogaritms from pynac in Sage. Fixing the numeric evaluation should be on a separate ticket.
I think you might want to try
as a first step. But I don't see immediate Sage access to Ginac's
other than the regular polylog. However, Pynac's code doesn't seem to be missing too much of Ginac's stuff; some things are commented out, but not much.
Here is where ask.sagemath.org is NOT so helpful - no guarantee that the person who would know this best is reading. I'll ping him and see if he might give a sense of how you could write a wrapper (there are lots of good examples in Sage itself); presumably you could also access it via the C interface.
Incidentally, mpmath does not appear to currently support multiple polylogs.
I'm not sure how much help this will be, but it looks to me like Sage has GiNaC built in, so there should be a way to create and manipulate GiNaC objects from Sage . . . it looks like the contents of, e.g.,
Good luck :)
Asked: Sep 30 '10
Seen: 211 times
Last updated: Oct 01 '10
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