GMP Functions
PHP Manual

gmp_hamdist

Hamming distance

Description

int gmp_hamdist(GMPintstring $num1, GMPintstring $num2)

Returns the hamming distance between num1 and num2. Both operands should be non-negative.

Parameters

num1

A GMP object, an int, or a string that can be interpreted as a number following the same logic as if the string was used in gmp_init with automatic base detection (i.e. when base is equal to 0).

It should be positive.

num2

A GMP object, an int, or a string that can be interpreted as a number following the same logic as if the string was used in gmp_init with automatic base detection (i.e. when base is equal to 0).

It should be positive.

Return Values

The hamming distance between num1 and num2, as an int.

Examples

Example #1 gmp_hamdist example

<?php
$ham1 = gmp_init("1001010011", 2);
$ham2 = gmp_init("1011111100", 2);
echo gmp_hamdist($ham1, $ham2) . "\n";

/* hamdist is equivalent to: */
echo gmp_popcount(gmp_xor($ham1, $ham2)) . "\n";
?>

The above example will output:

6
6

See Also

  • gmp_popcount
  • gmp_xor