Get-WilliamsRIndicator.ps1

<# 
.SYNOPSIS
    Calculates the Williams %R indicator for given high, low, and close prices.

.DESCRIPTION
    The Get-WilliamsRIndicator function calculates the Williams %R indicator, which measures 
    the level of overbought or oversold conditions in the market.

.PARAMETER High
    An array of high prices.

.PARAMETER Low
    An array of low prices.

.PARAMETER Close
    An array of close prices.

.PARAMETER Period
    The period over which to calculate the Williams %R indicator.

.EXAMPLE
    $high = 1..10
    $low = 5..14
    $close = 3..12
    $period = 5

    $williamsR = Get-WilliamsRIndicator -High $high -Low $low -Close $close -Period $period
    $williamsR
#>
function Get-WilliamsRIndicator {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true)]
        [double[]]$High,

        [Parameter(Mandatory = $true)]
        [double[]]$Low,

        [Parameter(Mandatory = $true)]
        [double[]]$Close,

        [Parameter(Mandatory = $true)]
        [int]$Period
    )

    $results = @()

    # Check if the arrays have any null values
    $Low = $Low | Where-Object { $_ -ne $null }
    $Close = $Close | Where-Object { $_ -ne $null }

    # Verify that the arrays have the same number of elements as the $High array
    if ($Low.Count -ne $High.Count) {
        throw "The number of elements in the Low and High arrays do not match."
    }

    if ($Close.Count -ne $High.Count) {
        throw "The number of elements in the Close and High arrays do not match."
    }

    # Initialize arrays if not already done
    if ($Low.Count -eq 0) {
        $Low = @()
        for ($i=0; $i -lt $High.Count; $i++) {
            $Low += $High[$i]
        }
    }

    if ($Close.Count -eq 0) {
        $Close = @()
        for ($i=0; $i -lt $High.Count; $i++) {
                $Close += $High[$i]
        }
    }

    # Populate results array with Williams %R values
    for ($i=$Period-1; $i -lt $High.Count; $i++) {
        $highestHigh = ($High[($i-$Period+1)..$i] | Measure-Object -Maximum).Maximum
        $lowestLow = ($Low[($i-$Period+1)..$i] | Measure-Object -Minimum).Minimum
        $williamsR = (($highestHigh - $Close[$i]) / ($highestHigh - $lowestLow)) * -100
        $results += $williamsR
    }

    return $results
}