public function Fraction::gcd in Fraction 7

Calculate the fraction's greatest common divisor using Euclid's algorithm.

Return value

string Returns the greatest common divisor.

1 call to Fraction::gcd()

Fraction::reduce in ./fraction.class.inc

Reduce the fraction to its simplest form.

File

./fraction.class.inc, line 222

Fraction class

Class

Fraction

@file Fraction class

Code

public function gcd() {

  // Get the numerator and denominator.
  $numerator = $this
    ->getNumerator();
  $denominator = $this
    ->getDenominator();

  // Make sure both numbers are positive.
  $a = str_replace('-', '', $numerator);
  $b = str_replace('-', '', $denominator);

  // Euclid's algorithm gives us the greatest common divisor.
  // Use BCMath's modulus function if available.
  if (function_exists('bcmod')) {
    while ($b != 0) {
      $t = $b;
      $b = bcmod($a, $b);
      $a = $t;
    }
  }
  else {
    while ($b != 0) {
      $t = $b;
      $b = $a % $b;
      $a = $t;
    }
  }
  return (string) $a;
}