PHP gmp_sqrt函数代码示例

 /**
  * @param string $left_operand
  * @param string $right_operand
  * @return string
  */
 public function sqrt($operand)
 {
     $result = gmp_sqrt($operand);
     return gmp_strval($result);
 }

<?php

var_dump(gmp_strval(gmp_sqrt(-2)));
var_dump(gmp_strval(gmp_sqrt("-2")));
var_dump(gmp_strval(gmp_sqrt("0")));
var_dump(gmp_strval(gmp_sqrt("2")));
var_dump(gmp_strval(gmp_sqrt("144")));
$n = gmp_init(0);
var_dump(gmp_strval(gmp_sqrt($n)));
$n = gmp_init(-144);
var_dump(gmp_strval(gmp_sqrt($n)));
$n = gmp_init(777);
var_dump(gmp_strval(gmp_sqrt($n)));
var_dump(gmp_sqrt($n, 1));
var_dump(gmp_sqrt());
var_dump(gmp_sqrt(array()));
echo "Done\n";

 /**
  * Returns the (integer) square root of a Math_Integer number
  *
  * @param object Math_Integer $int1
  * @return object Math_Integer on success, PEAR_Error otherwise
  * @access public
  */
 function &sqrt(&$int1)
 {
     /*{{{*/
     if (PEAR::isError($err = Math_IntegerOp::_validInt($int1))) {
         return $err;
     }
     switch (MATH_INTLIB) {
         /*{{{*/
         case 'gmp':
             $tmp = gmp_strval(gmp_sqrt($int1->getValue()));
             break;
         case 'bcmath':
             $tmp = bcsqrt(-1, $int1->getValue());
             break;
         case 'std':
             $tmp = intval(sqrt($int1->getValue()));
             break;
     }
     /*}}}*/
     return new Math_Integer($tmp);
 }

 function bcsqrt($x)
 {
     return gmp_strval(gmp_sqrt($x));
 }

$a = gmp_init("0xff");
echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "\n";
gmp_setbit($a, 0, false);
// clear bit at index 0
echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "\n";
// gmp_sign
echo gmp_sign("500") . "\n";
// positive
echo gmp_sign("-500") . "\n";
// negative
echo gmp_sign("0") . "\n";
// zero
// gmp_sqrt
$sqrt1 = gmp_sqrt("9");
$sqrt2 = gmp_sqrt("7");
$sqrt3 = gmp_sqrt("1524157875019052100");
echo gmp_strval($sqrt1) . "\n";
echo gmp_strval($sqrt2) . "\n";
echo gmp_strval($sqrt3) . "\n";
// gmp_sqrtrem
list($sqrt1, $sqrt1rem) = gmp_sqrtrem("9");
list($sqrt2, $sqrt2rem) = gmp_sqrtrem("7");
list($sqrt3, $sqrt3rem) = gmp_sqrtrem("1048576");
echo gmp_strval($sqrt1) . ", " . gmp_strval($sqrt1rem) . "\n";
echo gmp_strval($sqrt2) . ", " . gmp_strval($sqrt2rem) . "\n";
echo gmp_strval($sqrt3) . ", " . gmp_strval($sqrt3rem) . "\n";
// gmp_strval
$a = gmp_init("0x41682179fbf5");
printf("Decimal: %s, 36-based: %s" . PHP_EOL, gmp_strval($a), gmp_strval($a, 36));
// gmp_sub
$sub = gmp_sub("281474976710656", "4294967296");

 public function Sqr($left)
 {
     return $this->string(gmp_sqrt($left));
 }

 /**
  * Get the square route
  *
  * @access public
  * @return self
  */
 public function sqrt()
 {
     $result = gmp_sqrt($this->getRawValue());
     return static::factory($result);
 }

 /**
  * @param string $left_operand
  * @param string $right_operand
  * @return string
  */
 public function sqrt($operand)
 {
     return gmp_strval(gmp_sqrt($operand));
 }

 /**
  * Return all prime factors of this number
  *
  * The keys (prime factors) will be strings
  * The values (exponents will be integers
  *
  * Adapted from http://www.thatsgeeky.com/2011/03/prime-factoring-with-php/
  *
  * @return array [primeFactor => exponent,...]
  */
 public function primeFactors()
 {
     $number = $this->cloneValue();
     $divisor = 2;
     $zero = gmp_init(0);
     $one = gmp_init(1);
     $dmax = gmp_sqrt($number);
     $factors = array();
     $sieve = array_fill(1, intval(gmp_strval($dmax)), 1);
     do {
         $rFlag = false;
         while (gmp_cmp(gmp_mod($number, $divisor), $zero) == 0) {
             $factors[$divisor] = isset($factors[$divisor]) ? $factors[$divisor] + 1 : 1;
             $number = gmp_div_q($number, $divisor);
             $rFlag = true;
         }
         if ($rFlag) {
             $dmax = gmp_sqrt($number);
         }
         if (gmp_cmp($number, $one) > 0) {
             for ($i = $divisor; gmp_cmp($i, $dmax) <= 0; $i += $divisor) {
                 $sieve[$i] = 0;
             }
             do {
                 $divisor++;
             } while (gmp_cmp($divisor, $dmax) < 0 && $sieve[$divisor] != 1);
             if (gmp_cmp($divisor, $dmax) > 0) {
                 $key = gmp_strval($number);
                 $factors[$key] = isset($factors[$key]) ? $factors[$key] + 1 : 1;
             }
         }
     } while (gmp_cmp($number, $one) > 0 && gmp_cmp($divisor, $dmax) <= 0);
     return $factors;
 }

 /**
  * Calculates & returns the integer portion of the square root.
  *
  * @param  string $a  The first number.
  * @return string
  */
 public function sqrt($a)
 {
     return gmp_strval(gmp_sqrt($a));
 }