How can pi be calculated for a given number of digits in PHP?

Question

How can I calculate the pi value in PHP to X decimal numbers.

4 decimal points

3,141

64 decimal points

3.141592653589793238462643383279502884197169399375105820974944592

Answer 1

Found source for broken link @Konamiman.

Compared to the results: http://www.angio.net/pi/digits/50.txt , they are the same.

// Source: http://mgccl.com/2007/01/22/php-calculate-pi-revisited
function bcfact($n)
{
    return ($n == 0 || $n== 1) ? 1 : bcmul($n,bcfact($n-1));
}
function bcpi($precision)
{
    $num = 0;$k = 0;
    bcscale($precision+3);
    $limit = ($precision+3)/14;
    while($k < $limit)
    {
        $num = bcadd($num, bcdiv(bcmul(bcadd('13591409',bcmul('545140134', $k)),bcmul(bcpow(-1, $k), bcfact(6*$k))),bcmul(bcmul(bcpow('640320',3*$k+1),bcsqrt('640320')), bcmul(bcfact(3*$k), bcpow(bcfact($k),3)))));
        ++$k;
    }
    return bcdiv(1,(bcmul(12,($num))),$precision);
}

echo bcpi(1000);

Answer 2

Computing PI in php?

Why count when we already have a constant M_PI?

M_PIcontains value 3.14159265358979323846.

10,000 decimal places for PI are pretty many.

: http://www.php.net/manual/en/math.constants.php

Answer 3

Pi . , Pi . , substr . , , pi, google.

Answer 4

PHP , , 22/7 - PI, , PI, PHP. , PI .