PowerShell/docs/write-pi.md
2024-11-08 12:40:31 +01:00

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The *write-pi.ps1* Script
===========================
This PowerShell script calculates and writes the digits of the mathematical constant PI.
Parameters
----------
```powershell
/home/markus/Repos/PowerShell/scripts/write-pi.ps1 [[-digits] <Int32>] [<CommonParameters>]
-digits <Int32>
Specifies the number of digits to list (1000 by default)
Required? false
Position? 1
Default value 1000
Accept pipeline input? false
Accept wildcard characters? false
[<CommonParameters>]
This script supports the common parameters: Verbose, Debug, ErrorAction, ErrorVariable, WarningAction,
WarningVariable, OutBuffer, PipelineVariable, and OutVariable.
```
Example
-------
```powershell
PS> ./write-pi.ps1
3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342...
```
Notes
-----
Author: Markus Fleschutz | License: CC0
Related Links
-------------
https://github.com/fleschutz/PowerShell
Script Content
--------------
```powershell
<#
.SYNOPSIS
Writes PI
.DESCRIPTION
This PowerShell script calculates and writes the digits of the mathematical constant PI.
.PARAMETER digits
Specifies the number of digits to list (1000 by default)
.EXAMPLE
PS> ./write-pi.ps1
3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342...
.LINK
https://github.com/fleschutz/PowerShell
.NOTES
Author: Markus Fleschutz | License: CC0
#>
param([int]$digits = 1000)
function Write-Pi ( $digits ) {
$Big = [bigint[]](0..10)
$ndigits = 0
$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 = $nr
Write-Host "$($n)." -noNewline
$ndigits++
$nr = $Big[10] * ( $r - $n * $t )
$n = ( ( $Big[10] * ( 3 * $q + $r ) ) / $t ) - 10 * $n
$q *= $Big[10]
$r = $nr
while ($ndigits -lt $digits) {
if ($Big[4] * $q + $r - $t -lt $n * $t) {
Write-Host "$n" -noNewline
$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 = $nr
}
}
Write-Host "... ($digits digits)"
}
try {
Write-Pi $digits
exit 0 # success
} catch {
"⚠️ Error in line $($_.InvocationInfo.ScriptLineNumber): $($Error[0])"
exit 1
}
```
*(generated by convert-ps2md.ps1 as of 11/08/2024 12:40:23)*