Get-RandomWeighted.ps1
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<#PSScriptInfo
.VERSION 1.0.0.2 .GUID cbd7128c-717b-4644-aab2-8617d00e5359 .AUTHOR SmallFoxx .COMPANYNAME SmallFoxx .COPYRIGHT The MIT License (MIT) .TAGS Random Weighted Integer List .LICENSEURI https://opensource.org/licenses/MIT .PROJECTURI https://github.com/smallfoxx/poshstuff/blob/main/Get-RandomWeighted.ps1 .RELEASENOTES #> <# .SYNOPSIS Return a random result from weigthed values .DESCRIPTION Utilizing a key-value pair hashtable, the script will return a random result. In the hashtable, the keys need to be the entries you are looking randomize and their weights are the value of the pair. .PARAMETER TableWeight Key-value pair hashtable where the keys are the entries to be randomized and the values are their respective weights. These weigthed values must be integers unless the -Deeper switched is used. If the -Deeper switch is utilized, any decimal based numerical value can be used for the weight. .PARAMETER Iterations The number of times to pull a random entry. .PARAMETER Deeper When used, the process will assign a specific range based on their respective weights with a more accuracy. .EXAMPLE PS>$Colors = @{ "Red" = 5; "Blue" = 3; "Green" = 2} PS>Get-RandomWeighted -TableWeight $Colors Result will be a random color from Red, Blue, or Green. The results should be 'Red' about 50% of the time, 'Blue' about 30%, and 'Green' about 20%. .EXAMPLE PS>$Bob = Get-ADUser -Identity "BobSmith" PS>$Chris = Get-AdUser -Identity "ChrisFields" PS>$Debbie = Get-AdUser -Identity "DebbieReynolds" PS>$Ecru = Get-AdUser -Identity "EcruTeam" PS>$OnCallTable = @{ $Bob = 0.0423 $Chris = 0.5311 $Debbie = 0.5284 $Ecru = 0.3709 } PS>Get-RandomWeighted -TableWeight $OnCallTable -Deeper The Results will one of the 4 being picked based on weights. This means 'Bob' would be selected about 2.8%, 'Chris' about 36.1%, 'Debbie' about 35.9%, and 'Ecru' about 25.2%. .EXAMPLE PS>$Colors = @{ "Red" = 5; "Blue" = 3; "Green" = 2} PS>Get-RandomWeighted -TableWeight $Colors -Iterations 10000 -Deeper | Group-Object | Select-Object -Property Name,Count Name Count ---- ----- Blue 2930 Green 2002 Red 5068 This ran through a deeper randomization of the 3 colors 10,000 times, grouped the results, and displayed the names and counts of each result. Due to the nature of randomization, those counts will vary on each run but should be close to 30%, 20%, and 50% for Blue, Green, and Red respectively. .LINK Get-Random #> [CmdletBinding()] param( [hashtable]$TableWeight, [int64]$Iterations=1, [switch]$Deeper ) begin { Function New-Range { param( [parameter(ValueFromPipeline,ValueFromPipelineByPropertyName)] $Value, [parameter(ValueFromPipelineByPropertyName)] [decimal]$Weight=1 ) $PrevMaxRange = Get-MaxRange [PSCustomObject]@{ "Value"=$Value "Weight"=$Weight "MinRange"=$PrevMaxRange "MaxRange"=$PrevMaxRange+$Weight } } Function Get-MaxRange { param( $RangeList = $script:ranges ) [decimal](($RangeList | Measure-Object -Property MaxRange -Maximum).Maximum) } Function Get-WeightedResult { $WeightedResult = Get-Random -Minimum ([decimal]0) -Maximum (Get-MaxRange) $script:ranges | Where-Object { ($_.MinRange -lt $WeightedResult) -and ($_.MaxRange -ge $WeightedResult) } } Function Add-WeightToRange { param( $Value, [decimal]$Weight=1 ) If (-not $script:ranges) { $script:ranges = [System.Collections.ArrayList]@() } $ThisRange = New-Range -Value ($Value) -Weight ($Weight) $Null = $script:ranges.Add($ThisRange) } } process { If ($deeper) { ForEach ($key in $TableWeight.Keys) { Add-WeightToRange -Value $Key -Weight ($TableWeight.$Key) } 1..$Iterations | ForEach-Object { $ResultEntry = Get-WeightedResult $ResultEntry.Value } } else { $array = [System.Collections.ArrayList]@() ForEach ($key in $TableWeight.Keys) { $null = 1..([int64]($TableWeight.$key)) | ForEach-Object { $array.Add($key) } } 1..$Iterations | ForEach-Object { $array | Get-Random } } } |