ANN: DecInt 0.4 - Arithmetic for very large decimal integers

casevh@comcast.net casevh at comcast.net
Mon Dec 19 21:36:59 CET 2005


DecInt is a class that support arithmetic on very large decimal
integers.

CHANGES

Version 0.4 fixes a critical bug in version 0.3b. All users should
upgrade!

I have also created Windows binaries for GMPY that are specifically
tuned for AMD 32-bit processors and the Intel Pentium 4 processors.
These are experimental; I am not able to test them.

WHAT

DecInt can calculate the decimal form of the 42nd Mersenne prime, all
7,816,230 digits, in less than 21 seconds. And less than 6 seconds if
gmpy 1.01 is available.

Multiplication used a combination of 4-way Toom-Cook and Nussbaumer
convolution. Pure Python multiplication is only 10x slower than GMP's
hand optimised assembler code!

Division uses a new algorithm based on David M. Smith's division
algorithm. Pure Python division is 16x slower than GMP but can actually
be faster in some instances; for example, dividing a 2,000,000 digit
number by an 800,000 digit number.

DecInt can be found at http://home.comcast.net/~casevh/

Enjoy,

casevh



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