src/matrix.ps1
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function New-Matrix { <# .SYNOPSIS Utility wrapper function for creating matrices .DESCRIPTION New-Matrix is a wrapper function for the [Matrix] class and is intended to reduce the effort required to create [Matrix] objects. Use "New-Matrix | Get-Member" to see available methods: Adj: Return matrix adjugate ("classical adjoint") > Note: Available as a class method - [Matrix]::Adj Det: Return matrix determinant (even matrices larger than 3x3 > Note: Available as a class method - [Matrix]::Det Dot: Return dot product between matrix and one other matrix (with compatible size) > Note: Available as a class method - [Matrix]::Dot Clone: Return new matrix with identical values as original matrix Cofactor: Return cofactor for given row and column index pair > Example: $Matrix.Cofactor(0, 1) Indexes: Return list of "ij" pairs (useful for iterating through matrix values) > Example: (New-Matrix).Indexes() | ForEach-Object { "(i,j) = ($($_[0]),$($_[1]))" } Inverse: Return matrix inverse (Note: Det() must return non-zero value) > Note: Available as a class method - [Matrix]::Invert Multiply: Return result of multiplying matrix by scalar value (ex: 42) > Note: Available as a class method - [Matrix]::Multiply RemoveColumn: Return matrix with selected column removed RemoveRow: Return matrix with selected column removed Transpose: Return matrix transpose > Note: Available as a class method - [Matrix]::Transpose Trace: Return matrix trace (sum of diagonal elements) > Note: Available as a class method - [Matrix]::Trace *** All methods that return a [Matrix] object provide a "fluent" interface and can be chained *** *** All methods are "non destructive" and will return a clone of the original matrix (when applicable) *** .PARAMETER Size Size = @(number of rows, number of columns) .EXAMPLE $Matrix = 1..9 | matrix 3,3 #> [CmdletBinding()] [Alias('matrix')] [OutputType([Matrix])] Param( [Parameter(ValueFromPipeline = $True)] [Array] $Values, [Parameter(Position = 0)] [Array] $Size = @(2, 2), [Switch] $Diagonal ) Begin { $Matrix = New-Object 'Matrix' @($Size[0], $Size[1]) if ($Values.Count -gt 0) { $Values = $Values | Invoke-Flatten if ($Diagonal) { $Index = 0 foreach ($Pair in $Matrix.Indexes()) { $Row, $Column = $Pair if ($Row -eq $Column) { $Matrix.Rows[$Row][$Column] = $Values[$Index] $Index++ } } } else { $Matrix.Rows = $Values } } } End { if ($Input.Count -gt 0) { $Values = $Input | Invoke-Flatten if ($Diagonal) { $Index = 0 foreach ($Pair in $Matrix.Indexes()) { $Row, $Column = $Pair if ($Row -eq $Column) { $Matrix.Rows[$Row][$Column] = $Values[$Index] $Index++ } } } else { $Matrix.Rows = $Values } } $Matrix } } function Test-Matrix { <# .SYNOPSIS Test if a matrix is one or more of the following: - Diagonal - Square - Symmetric .EXAMPLE $A = 1..4 | New-Matrix 2,2 $A | Test-Matrix -Square # Returns True .EXAMPLE $A = 1..4 | New-Matrix 2,2 $A | Test-Matrix -Square -Diagonal # Returns False #> [CmdletBinding()] [OutputType([Bool])] Param( [Parameter(Position = 0, ValueFromPipeline = $True)] $Value, [Switch] $Diagonal, [Switch] $Square, [Switch] $Symmetric ) if ($Value.GetType().Name -eq 'Matrix') { $Result = $True if ($Diagonal) { $Result = $Result -and $Value.IsDiagonal() } if ($Square) { $Result = $Result -and $Value.IsSquare() } if ($Symmetric) { $Result = $Result -and $Value.IsSymmetric() } return $Result } $False } |