On Mar 1, 12:29 pm, "Anand Patil" <[EMAIL PROTECTED]> wrote: > Not sure if this is common knowledge yet but > Sympy,http://code.google.com/p/sympy, has a rational type.
I hadn't heard of this before, thanks for the link. Very nifty, lots of goodies not found in gmpy (although it seems to lack a modular inverse function and the linear congruence solver that can be derived from it making it of no value to me). Alas, it's written in Python. Who writes a math library in Python? Nevertheless, I thought I would try out the Rational numbers. Once I figured out how to use them, I converted my Polynomial Finder by Newton's Forward Difference Method program to use sympy instead of gmpy. I have a test case where I create 1 66 degree polynomial where the coefficients are large rationals. The polynomial was calculated flawlessly <partial output> ## sympy ## Term0: [66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, -66, 66, 0] ## ## Seq: [66, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 66] ## ## The Polynomial: ## ## ## 1 ## ------------------------------------------------------------------------------------------- * n**66 ## 8247650592082470666723170306785496252186258551345437492922123134388955774976000000000000000 ## ## ## -67 ## ------------------------------------------------------------------------------------------ * n**65 ## 249928805820680929294641524448045340975341168222589014937034034375422902272000000000000000 ## ## ## 67 ## --------------------------------------------------------------------------------------- * n**64 ## 230703513065243934733515253336657237823391847590082167634185262500390371328000000000000 But because they are calculated using Python, it took 175 seconds compared to 0.2 seconds for gmpy to do the same polynomial. So, I'll keep it around for it's neat features that gmpy doesn't have, but it won't replace gmpy for any serious work. > > In [2]: from sympy import * > > In [3]: Rational(21,4) > Out[3]: 21/4 > > In [4]: Rational(21,4)+Rational(3,4) > Out[4]: 6 -- http://mail.python.org/mailman/listinfo/python-list
