Thanks! _ will use that. On Friday, March 19, 2021 at 8:07:07 PM UTC-4 smi...@gmail.com wrote:
> See `npartitions` in sympy/ntheory/partitions_.py > <https://github.com/sympy/sympy/blob/706007ca2fe279020e099d36dd1db0e33123ac4c/sympy/ntheory/partitions_.py> > > >>> npartitions(10**3) > 24061467864032622473692149727991 > > /c > On Friday, March 19, 2021 at 6:43:55 PM UTC-5 rocky.b...@gmail.com wrote: > >> A little background first... >> >> I have been working on Mathics, <https://mathics.org/> a open-source >> implementation of the Wolfram Language. >> >> Mathics relies heavily on sympy. >> >> For a little while I have been working on ensuring that Steve Skiena's >> Combinatorica >> <https://www.abebooks.com/servlet/BookDetailsPL?bi=30794099489&searchurl=isbn%3D0201509431%26sortby%3D17&cm_sp=snippet-_-srp1-_-title1> >> works >> on Mathics. In doing this, I was looking for a sympy equivalent to >> PartitionsP[] >> <https://reference.wolfram.com/language/ref/PartitionsP.html>. >> >> I couldn't find anything so initially I was generating all of the >> partitions using sympy.utilities.iterables.partitions and then taking >> the length. >> >> This is horribly inefficent. Therefore I thought, I'd use the algorition >> in Skiena's book which makes use of Euler's recurrence for the number of >> partitions. >> >> It took a little bit of tweaking to get it to be reasonably efficient in >> Python. The current impelemtation is here >> <https://github.com/mathics/Mathics/blob/master/mathics/builtin/combinatorial.py#L105-L136> >> . >> >> This might be of interest and use in sympy as well, so I'd like to >> mention it here. >> >> And if there is already such a routine in sympy, I'd would be grateful to >> know about. >> >> Thanks. >> > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/77622aed-5ea7-42d1-b5a0-6fd07aceed7dn%40googlegroups.com.
