Windows Powershell 等效于此 Linux 命令，可将数字计算到小数点后 10000 位？

Question

我在社交媒体上看到过这个有趣的小命令，它输出 pi 到小数点后 10000 位。我想知道与此等效的 Windows Powershell 是什么？

echo "scale=10000; 4*a(1)" | bc -l

我知道我可以使用 Powershell Math library 来做基本的数学公式，但是如何将小数位数设置为 10000？

PS C:\Users\Me> [Math]::Atan(1)*4
3.14159265358979

Answer 1

.NET 中的 [Math] class only works with double so obviously you can't get more than 53 bits of precision. A few of its methods also support decimal so you'll get a little bit more digits but obviously no way near 10000 digits. There's no arbitrary precision 浮点类型，因此如果您不想从某些存储中检索数字，您完全可以自己计算数字 space

有BigInteger (PowerShell type accelerator name: [bigint]) though, which helps a lot since you won't need to do arbitrary precision math yourself. For example to calculate 10000 digits of π you can calculate 10000π and does the operations in integer or fixed point math

有many algorithms to do that such as this one:

还好Rosetta Code has a sample snippet to calculate π。声明以下函数后，只需调用 Get-Pi 10000 即可获得所需的输出

Function Get-Pi ( $Digits )
    {
    $Big = [bigint[]](0..10)
 
    $ndigits = 0
    $Output = ""
 
    $q = $t = $k = $Big[1]
    $r =           $Big[0]
    $l = $n =      $Big[3]
    # Calculate first digit
    $nr = ( $Big[2] * $q + $r ) * $l
    $nn = ( $q * ( $Big[7] * $k + $Big[2] ) + $r * $l ) / ( $t * $l )
    $q *= $k
    $t *= $l
    $l += $Big[2]
    $k = $k + $Big[1]
    $n = $nn
    $r = $nr
 
    $Output += [string]$n + '.'
    $ndigits++
 
    $nr = $Big[10] * ( $r - $n * $t )
    $n = ( ( $Big[10] * ( 3 * $q + $r ) ) / $t ) - 10 * $n
    $q *= $Big[10]
    $r = $nr
 
    While ( $ndigits -lt $Digits )
        {
        While ( $ndigits % 100 -ne 0 -or -not $Output )
            {
            If ( $Big[4] * $q + $r - $t -lt $n * $t )
                {
                $Output += [string]$n
                $ndigits++
                $nr = $Big[10] * ( $r - $n * $t )
                $n = ( ( $Big[10] * ( 3 * $q + $r ) ) / $t ) - 10 * $n
                $q *= $Big[10]
                $r = $nr
                }
            Else
                {
                $nr = ( $Big[2] * $q + $r ) * $l
                $nn = ( $q * ( $Big[7] * $k + $Big[2] ) + $r * $l ) / ( $t * $l )
                $q *= $k
                $t *= $l
                $l += $Big[2]
                $k = $k + $Big[1]
                $n = $nn
                $r = $nr
                }
            }
        $Output
        $Output = ""
        }
    }

Windows Powershell 等效于此 Linux 命令，可将数字计算到小数点后 10000 位？

Windows Powershell equivalent to this Linux command that calculates a number to 10000 decimal places?

powershell

math

decimal

precision