SWISS::CRC64 (3pm)

\s-1NAME\s0

\s-1CRC64\s0 - Calculate the cyclic redundancy check.

\s-1SYNOPSIS\s0

   use SWISS::CRC64;

   $crc = SWISS::CRC64::crc64("IHATEMATH");
   #returns the string "E3DCADD69B01ADD1"

   ($crc_low, $crc_high) = SWISS::CRC64::crc64("IHATEMATH");
   #returns two 32-bit unsigned integers, 3822890454 and 2600578513

\s-1DESCRIPTION\s0

SWISS-PROT + \s-1TREMBL\s0 use a 64-bit Cyclic Redundancy Check for the amino acid sequences.

The algorithm to compute the \s-1CRC\s0 is described in the \s-1ISO\s0 3309 standard. The generator polynomial is x64 + x4 + x3 + x + 1. Reference: W. H. Press, S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, \*(L"Numerical recipes in C\*(R", 2nd ed., Cambridge University Press. Pages 896ff.

Functions

crc64 string

Calculate the \s-1CRC64\s0 (cyclic redundancy checksum) for string. In array context, returns two integers equal to the higher and lower 32 bits of the \s-1CRC64\s0. In scalar context, returns a 16-character string containing the \s-1CRC64\s0 in hexadecimal format.

Alexandre Gattiker, [email protected]

Based on SPcrc, a C implementation by Christian Iseli, available at ftp://ftp.ebi.ac.uk/pub/software/swissprot/Swissknife/old/SPcrc.tar.gz