Get-StandardDeviation.ps1
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function Get-StandardDeviation { <# .Synopsis Gets the standard deviation of a series of numbers .Description Gets the standard deviation of a series of numbers .Example Get-StandardDeviation 2,4,6,8 #> param( # The series of numbers [Parameter(Mandatory=$true,ValueFromPipelineByPropertyName=$true,Position=0)] [Double[]] $Number ) begin { $numberSeries = @() } process { $numberSeries += $number } end { $scriptBlock = " # Start the total at zero `$total = 0 " foreach ($n in $numberSeries) { $scriptBlock += " # Add $n to the total `$total += $n " } $scriptBlock += " # The average is the total divided by the number of items $($numberSeries.Count) `$average = `$total / $($numberSeries.Count) `$deviationTotal = 0 " foreach ($n in $NumberSeries) { $scriptBlock += " # Add $n to the total `$deviationTotal += [Math]::Pow(($n - `$average), 2) " } $scriptBlock += " `$deviationAverage = `$deviationTotal / $($numberSeries.Count) `$standardDeviation = [Math]::Sqrt(`$deviationAverage) " $sb= [ScriptBlock]::Create($scriptBlock) $null = . $sb $standardDeviation } } |