Measure-Frequency.ps1

function Measure-Frequency {
    <#
        .SYNOPSIS
            Get the frequency distribution of a set.
        .DESCRIPTION
            This function will get the frequency distribution of a set (array) of data.
            It supports array types, as well as strings.
        .EXAMPLE
            Measure-Frequency $array
        .EXAMPLE
            Measure-Frequency $string -CaseSensitive
        .NOTES
            Author: Øyvind Kallstad
            Date: 10.02.2016
            Version: 1.0
    #>
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true, Position = 0)]
        $InputObject,

        [Parameter()]
        [switch] $CaseSensitive
    )

    try {
        if ($InputObject.GetType().Name -eq 'String') {
            if ($CaseSensitive) {
                $inputArray = $InputObject.ToCharArray()
            }
            else {
                $inputArray = $InputObject.ToLower().ToCharArray()
            }
        }
    
        else {
            $inputArray = $InputObject
        }

        $inputArray | Group-Object | Sort-Object -Descending -Property Count | ForEach-Object {
        
            $frequency = $_.Count / $inputArray.Length
            $percent = '{0:P0}' -f $frequency

            Write-Output ([PSCustomObject] [Ordered] @{
                Value = $_.Name
                Count = $_.Count
                Percent = $percent
                Frequency = $frequency
            })
        }
    }
    catch {
        Write-Warning $_.Exception.Message
    }
}