PowerShell for Math.NET Numerics

Purpose

PowerShell can utilize the math libraries of Math.NET Numerics and the processor-optimized Intel Math Kernel Library (MKL). To help coders get started, this article is a collection of PowerShell examples using Math.NET with Intel's MKL.

Download The Script

Because source code can be hard to read in a blog, you can download a script with all the examples: get the SEC505 zip file from the Downloads page of this blog, open the zip to the \Day1-PowerShell folder, and find the Math.NET.Numerics-Examples.ps1 script.

(In the zip file you'll find over a hundred other PowerShell scripts, all in the public domain, used in my SANS course Securing Windows and PowerShell Automation [SEC505].)

Background

Math.NET (www.MathDotNet.com) is a set of open source mathematical toolkits optimized for ease of use and performance. The Math.NET libraries are compatible with the Microsoft .NET Framework and the Mono project, which makes them accessible to PowerShell too. The toolkits are available for free under the MIT/X11 license, which is even more liberal than the GNU Public License (except for the Intel MKL, which has its own license, but it is still free for your own use when obtained with Math.NET).

One part of the Math.NET project is Math.NET Numerics, which is especially useful for math computations in science and engineering. It includes methods for statistics, probability, random numbers, linear algebra, interpolation, regression, optimization problems, and more. The project includes hardware-optimized native libraries to maximize performance on x64 or x86 processors, such as Intel's Math Kernel Library (MKL).

The majority of computers used by scientists and engineers worldwide run Microsoft Windows. PowerShell is built into Windows and is relatively easy to learn. Think of PowerShell as "simplified C#" for use in a command shell and in scripts. Just like C#, PowerShell can access the .NET Framework; in fact, PowerShell itself is a .NET Framework application.

Why PowerShell?

For scientists and engineers, PowerShell is great for:

• utilizing the Intel Math Kernel Library (MKL) through Math.NET Numerics,
• managing long-running, complex compute jobs and scheduled tasks,
• orchestrating large-scale parallel MATLAB workloads in Azure,
• managing Machine Learning experiments in Azure,
• managing tasks on remote Linux boxes using a PowerShell port of ssh,
• programmatically interacting with REST/SOAP/XML/JSON web applications,
• doing quick-and-dirty distributed computing with Workflows and Remoting,
• running processes concurrently with RunSpaces or background jobs,
• importing/exporting data with Excel spreadsheets,
• quickly prototyping new ideas which could then be later ported to C# because of the similarities between PowerShell and C#,
• playing nice with the built-in support for Ubuntu bash on Windows 10 and later,
• and using the Posh-Git PowerShell module with GitHub Desktop.

For data visualization, PowerShell and Math.NET can export data for display in MATLAB or Excel, or you could script it yourself using the built-in .NET classes for visualization.

As an uncompiled and dynamically-typed language, PowerShell will never come close to the performance of C/C++, but with Math.NET and the Intel MKL provider, this might be less of an issue. On the other hand, C/C++ will never match the convenience (and fun) of using PowerShell with Math.NET or Python with NumPy. Can PowerShell script code be compiled? Yes and no: in some cases, parts of the script are compiled automatically on-the-fly, but we don't have much control over the JIT-ing when it occurs.

Math.NET Installation

See the main Math.NET Numerics project site, the source of all the examples: http://numerics.mathdotnet.com

If you do not have PowerShell 5.0 or later, get the NUGET.EXE package installer: http://docs.nuget.org/consume/installing-nuget

If you do have PowerShell 5.0 or later, create an appropriate parent folder (perhaps C:\Program Files\MathNet), then install the binaries there:

Install-Package -ProviderName NuGet -Name MathNet.Numerics -Destination C:\SomeFolder -Force

Or, if you are using NUGET.EXE, create an appropriate parent folder, then install the Math.NET Numerics binaries there:

cd C:\SomeFolder
.\nuget.exe install MathNet.Numerics

Optionally, install the Intel MKL Native Provider. For simplicity, you can copy the two MKL DLLs (libiomp5md.dll and MathNet.Numerics.MKL.dll) from the package's Content folder into the same folder as your PowerShell scripts, but see this page for the use of other default paths instead. While the installation of the Intel MKL is, strictly speaking, optional, it will greatly accelerate linear algebra tasks.

Using PowerShell 5.0 or later, install the Intel MKL Native Provider:

Install-Package -ProviderName NuGet -Name MathNet.Numerics.MKL.Win-x64 -Destination C:\SomeFolder -Force

Or, do the same with NUGET.EXE:

.\nuget.exe install MathNet.Numerics.MKL.Win-x64

Optionally, install the MathNet.Numerics.Data.Text package for TSV/CSV files and NIST Matrix Market files:

Install-Package -ProviderName NuGet -Name MathNet.Numerics.Data.Text -Destination C:\SomeFolder -Force
.\nuget.exe install MathNet.Numerics.Data.Text

Optionally, install support for MATLAB Level-5 MAT files:

Install-Package -ProviderName NuGet -Name MathNet.Numerics.Data.Matlab -Destination C:\SomeFolder -Force
.\nuget.exe install MathNet.Numerics.Data.Matlab

Add Types and Create Accelerators

At the beginning of your script, you would load the Math.NET modules and create "solution accelerators", which are just short aliases for longer commands. In all the examples in this article, you will see aliases with names like "[M]" and "[V]" for creating matrices or vectors using Math.NET. These are using the accelerators defined here.

# Switch to the folder where you installed the Math.NET package(s) for
# your version of the .NET Framework (your folder will be different):
cd F:\Temp\Hashing\MathNet.Numerics.3.11.1\lib\net40

# Load the Math.NET Numerics DLL (nearly always required):
 Add-Type -Path .\MathNet.Numerics.dll

# Load the MathNet.Numerics.Data.Text DLL (optional):
 Add-Type -Path .\MathNet.Numerics.Data.Text.dll

# [M]: Create an accelerator shortcut [M] for use of Math.NET matrices:
 psobject].Assembly.GetType("System.Management.Automation.TypeAccelerators")::Add('M','MathNet.Numerics.LinearAlgebra.Matrix[Double]')

# [V]: Create an accelerator shortcut [V] for use of Math.NET vectors:
 [psobject].Assembly.GetType("System.Management.Automation.TypeAccelerators")::Add('V','MathNet.Numerics.LinearAlgebra.Vector[Double]')

# [STAT]: Create an accelerator shortcut [STAT] for use of MathNet statistics:
 [psobject].Assembly.GetType("System.Management.Automation.TypeAccelerators")::Add('STAT','MathNet.Numerics.Statistics.Statistics')

# [FUNC]: Create an accelerator shortcut [FUNC] for use of MathNet special functions:
 [psobject].Assembly.GetType("System.Management.Automation.TypeAccelerators")::Add('FUNC','MathNet.Numerics.SpecialFunctions')

You can also simply assign the classes to variables instead of using accelerators:

$MATRIX = [MathNet.Numerics.LinearAlgebra.Matrix[Double]]
$VECTOR = [MathNet.Numerics.LinearAlgebra.Vector[Double]]
$STAT = [MathNet.Numerics.Statistics.Statistics]
$FUNC = [MathNet.Numerics.SpecialFunctions]

Intel Math Kernel Library (MKL) Native Provider

# Enable the use of Intel MKL for linear algebra:
[MathNet.Numerics.Control]::UseNativeMKL("Auto")

# Confirm the switch from "Managed" to "Intel MKL":
 [MathNet.Numerics.Control]::LinearAlgebraProvider

# If you want to switch back to the default, slower, managed .NET code:
 [MathNet.Numerics.Control]::UseManaged()

Intel MKL Performance Testing

Below are the results of some tests using Math.NET with the Intel MKL provider. The goal is to offload the heavy number crunching from PowerShell and the .NET Framework to compiled modules which have been hand-tuned for maximum performance. It's the same strategy used by Python and NumPy. You can also embed C# code inside your PowerShell script, if necessary, and have it compiled on-the-fly to maximize performance for that part of the script (it's not unusual for a script or application to spend 90% of its time in a fast loop or in another task that only represents a small number of lines of code in the overall script or app).

Here are the test system specs for reference:

• Intel MKL x64 libiomp5md.dll file version 5.0.2015.609 (Sept 2015)
• Intel Core i7-4790 CPU @ 3.60GHz
• 32GB Memory (DDR3 1600)
• Windows 10 Pro (Build 10.0.10586.122)
• PowerShell 5.0.10586.122
• CLR Version 4.0.30319.42000

Multiply two 2000×2000 matrices of random doubles:
With Default: 4720.48ms average
With Intel MKL: 350.09ms average
MKL Increase: 13.5X

1..10 | ForEach { Measure-Command -Expression { [M]::Build.Random(2000,2000) * [M]::Build.Random(2000,2000) } } | Measure-Object -Property TotalMilliseconds -Average

Compute eigenvalues and eigenvectors on a 1000×1000 matrix of random doubles:
With Default: 12554.58ms average
With Intel MKL: 694.03ms average
MKL Increase: 18.1X

1..10 | ForEach { Measure-Command -Expression { ([M]::Build.Random(1000,1000)).Evd() } } | Measure-Object -Property TotalMilliseconds -Average

Compute single value decomposition on a 1000×1000 matrix of random doubles:
With Default: 11167.04ms average
With Intel MKL: 362.52ms average
MKL Increase: 30.8X

 1..10 | ForEach { Measure-Command -Expression { ([M]::Build.Random(1000,1000)).Svd() } } | Measure-Object -Property TotalMilliseconds -Average

Compute the inverse of a 1000×1000 matrix of random doubles:
With Default: 14536.91ms average
With Intel MKL: 64.10ms average
MKL Increase: 226.8X

1..10 | ForEach { Measure-Command -Expression { ([M]::Build.Random(1000,1000)).Inverse() } } | Measure-Object -Property TotalMilliseconds -Average

Compute the determinant of a 1000×1000 matrix of random doubles:
With Default: 371.14ms average
With Intel MKL: 39.61ms average
MKL Increase: 9.4X

1..10 | ForEach { Measure-Command -Expression { ([M]::Build.Random(1000,1000)).Determinant() } } | Measure-Object -Property TotalMilliseconds -Average

Constants

[MathNet.Numerics.Constants] | Get-Member -Static

[MathNet.Numerics.Constants]::Pi
 [MathNet.Numerics.Constants]::Avogadro
 [MathNet.Numerics.Constants]::ProtonMass

Creating Matrices

# Create a dense matrix of random numbers(3 rows, 4 columns):
$matrix = [MathNet.Numerics.LinearAlgebra.Matrix[Double]]::Build.Random(3, 4)

# Create a dense zero-vector of length ten as [Double[]]:
 $vector = [MathNet.Numerics.LinearAlgebra.Vector[Double]]::Build.Dense(10)

# Create a dense matrix of random numbers(3 rows, 4 columns):
 [M]::Build.Random(3, 4)

# Create a dense zero-vector of length ten:
 [V]::Build.Dense(10)

# 3x4 dense matrix filled with zeros:
 [M]::Build.Dense(3, 4)

# 3x4 dense matrix filled with 1.0:
 [M]::Build.Dense(3, 4, 1.0)

# 3x4 dense matrix where each field is initialized using a function:
 function myfunc ($i, $j){ (100 * $i) + $j }
 [M]::Build.Dense(3, 4, (myfunc -i 3 -j 1) )

# 3x4 square dense matrix with each diagonal value set to 2.0:
 [M]::Build.DenseDiagonal(3, 4, 2.0)

# 3x3 dense identity matrix:
 [M]::Build.DenseIdentity(3)

# 3x4 dense random matrix sampled from a Gamma distribution:
 $gammadist = [MathNet.Numerics.Distributions.Gamma]::Sample( 1.0, 5.0 )
 [M]::Build.Random(3, 4, $gammadist )

# Create a matrix in column major order (column by column):
 [Double[]] $array = @( 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12 )
 [M]::Build.DenseOfColumnMajor(3,4,$array)

# Create a matrix from arrays representing columns:
 [Double[]] $d1 = @( 1,4,7 )
 [Double[]] $d2 = @( 2,5,8 )
 [Double[]] $d3 = @( 3,6,9 )
 [M]::Build.DenseOfColumnArrays( @($d1,$d1,$d3) )

# Create a matrix of column vectors:
 [M]::Build.DenseOfColumnVectors( [V]::Build.Random(3), [V]::Build.Random(3) )
 

Creating Vectors

# Create a standard-distributed random vector of length 10:[V]::Build.Random(10)

# Create an all-zero vector of length 10:
 [V]::Build.Dense(10)

# Create a vector where each field is initialized using a function:
 function myfunc ($i){ $i * $i }
 [V]::Build.Dense(10, (myfunc -i 3) )

# Create a vector from an array of Double:
 [Double[]] $d1 = @( 1,2,3,4,5 )
 [V]::Build.DenseOfArray( $d1 )

Matrix and Vector Arithmetic

# Create a matrix and vector to play around with:
[Double[]] $d1 = @( 1,4,7 )
[Double[]] $d2 = @( 2,5,8 )
[Double[]] $d3 = @( 3,6,9 )
[Double[]] $d4 = @( 10,20,30 )
$m = [M]::Build.DenseOfColumnArrays( @($d1,$d1,$d3) )
$v = [V]::Build.DenseOfArray( $d4 )

# Common arithmetic operators:
 $m * $v
 $m + (2 * $m)

# Instance methods:
 $m | Get-Member
 $m.Multiply( $v )
 $m.Add( $m.Multiply(2) )
 $m.Transpose()
 $m.Inverse()
 $m.Nullity()
 $m.Kernel()
 $v.Sum()

# Instance methods for in-place operations:
 $m.Multiply( $v, $v ) #Second arg captures output
 $m.Multiply( 3, $m ) #Value of $m changes

Manipulating Matrices and Vectors

$m[0,0] # Returns row 0, column 0
$m[2,0] # Returns row 2, column 0
$m[0,2] # Returns row 0, column 2
$m[0,2] = -1.0 # Assigns row 0, column 2 to -1.0

$m.Column(2) # Returns entire 3rd column
 $m.Row(1) # Returns entire 2nd row

$m.SubMatrix(1,2,1,2) # Returns new matrix from an existing one

$m.ClearColumn(2) # Set 3rd column to all zeros
 $m.Clear() # Set all columns to all zeros

Displaying Matrix and Vector Data

$m.RowCount # Returns count of rows
$m.ColumnCount # Returns count of columns

$m.ToColumnArrays() # Emits an array of all values by column
 $m.ToRowArrays() # Emits an array of all values by row

$m.ToMatrixString() # A 2D matrix as a string for printing

$v = [V]::Build.Random(30) # Fill a vector to have something to display
 $v.Count # Returns total number of items in vector
 $v.ToArray() # Returns array of items
 $v # Same as $v.ToArray()
 $v.ToString(5,80) # max per column = 5, max columns = 80

Generating Data

# List the generator functions supported:
[MathNet.Numerics.Generate] | Get-Member -Static

# Generate a range from 1..15, stepping by 1:
 [MathNet.Numerics.Generate]::LinearRange(1,1,15)

# Generate a range from 100..2000, stepping by 50:
 [MathNet.Numerics.Generate]::LinearRange(100,50,2000)

# Generate a sine wave of a given length, sampling rate, frequency, and amplitude:
 [MathNet.Numerics.Generate]::Sinusoidal(15, 1000, 100, 10)

# Generate 100 random numbers, uniformly distributed between 0 and 1:
 [MathNet.Numerics.Generate]::Uniform(100)

Random Numbers

# Generate 1000 random numbers between 0 and 1 using the
# System.Security.Cryptography.RandomNumberGenerator class:
[Double[]] $samples = [MathNet.Numerics.Random.CryptoRandomSource]::Doubles(1000)

# Overwrite the $samples array with new random numbers:
 [MathNet.Numerics.Random.CryptoRandomSource]::Doubles($samples)

# Generate an infinite sequence of random numbers:
 ForEach ( $num in [MathNet.Numerics.Random.CryptoRandomSource]::DoubleSequence() ){ $num }

# Fill an array of Byte[] with random bytes using the System.Random class:
 [System.Byte[]] $buffer = 1..100
 $rng = [MathNet.Numerics.Random.SystemRandomSource]::Default
 $rng.NextBytes( $buffer )
 $buffer -join ','

# Fill an array of Int32[] with random numbers between 4 and 999:
 [Int32[]] $buffer = 1..100
 $rng = [MathNet.Numerics.Random.SystemRandomSource]::Default
 $rng.NextInt32s( $buffer, 4, 999 )
 $buffer -join ','

# Generate a random seed using System.Security.Cryptography.RandomNumberGenerator:
 [MathNet.Numerics.Random.RandomSeed]::Robust()

# Generate five random Doubles using 42 as a seed:
 [MathNet.Numerics.Random.SystemRandomSource]::Doubles( 5, 42 )

# With Mersenne Twister 19937 generator, make five Doubles with a seed of 42:
 [MathNet.Numerics.Random.MersenneTwister]::Doubles( 5, 42 )

# With Multiply-with-Carry XOR-Shift generator, make five Doubles with a seed
 # of 42 and a=9, c=6, x1=11, x2=12:
 [MathNet.Numerics.Random.Xorshift]::Doubles( 5, 42, 9, 6, 11, 12 )

Distance Metrics

# Sum of Absolute Difference (SAD):
[MathNet.Numerics.Distance]::SAD( [Double] 44, [Double] 55 )

# Sum of Squared Difference (SSD):
 [MathNet.Numerics.Distance]::SSD( [Double] 44, [Double] 55 )

# Euclidean Distance:
 [MathNet.Numerics.Distance]::Euclidean( [Double] 44, [Double] 55 )

# Hamming Distance:
 [MathNet.Numerics.Distance]::Hamming( [Double] 44, [Double] 55 )

Descriptive Statistics

# There are four main classes with static methods for statistics:
[MathNet.Numerics.Statistics.Statistics] | Get-Member -Static

# Optimized for single-dimensional arrays:
 [MathNet.Numerics.Statistics.ArrayStatistics] | Get-Member -Static

# Optimized for very large data sets:
 [MathNet.Numerics.Statistics.StreamingStatistics] | Get-Member -Static

# Optimized for sorted arrays:
 [MathNet.Numerics.Statistics.SortedArrayStatistics] | Get-Member -Static

# Generate some Double[] data for the examples below:
 [Double[]] $data = [MathNet.Numerics.Random.CryptoRandomSource]::Doubles(1000)

# Create an accelerator shortcut [STAT] for use of MathNet.Numerics.Statistics.Statistics:
 [psobject].Assembly.GetType("System.Management.Automation.TypeAccelerators")::Add('STAT','MathNet.Numerics.Statistics.Statistics')

# Common statistical calculations with unsorted data:
 [MathNet.Numerics.Statistics.Statistics]::Mean($data) #Mean or average, using full class name
 [STAT]::Mean($data) #Mean or average, but using the solution accelerator
 [STAT]::Median($data) #Median
 [STAT]::Minimum($data) #Minimum
 [STAT]::Maximum($data) #Maximum
 [STAT]::PopulationVariance($data) #Variance
 [STAT]::PopulationStandardDeviation($data) #Standard Deviation
 [STAT]::Covariance($data, $data) #Covariance

# Compute both mean and standard deviation simultaneously for efficiency:
 $both = [MathNet.Numerics.Statistics.ArrayStatistics]::MeanStandardDeviation($data)
 $both.Item1 #mean
 $both.Item2 #standard deviation

# When $data is sorted ascending, use SortedArrayStatistics instead:
 [MathNet.Numerics.Statistics.SortedArrayStatistics]::Median($data)

# Create a histogram of $data with 10 buckets:
 $hist = New-Object -TypeName MathNet.Numerics.Statistics.Histogram -ArgumentList $data,10
 $hist.BucketCount
 $hist.Item(0) #First bucket
 $hist.Item(9) #Tenth bucket
 $hist.Item(0).Count
 $hist.Item(0).LowerBound
 $hist.Item(0).UpperBound
 $hist.Item(0).Width

# Output each bucket from histogram with properties (get the script with better formatting):
 function Get-Bucket ( $Histogram )
 {
 $bucket = ' ' | select BucketIndex,Count,LowerBound,UpperBound,Width
 $lastbucket = $Histogram.BucketCount
 for ($i = 0 ; $i -lt $lastbucket ; $i++)
 {
 $bucket.BucketIndex = $i
 $bucket.Count = $Histogram.Item($i).Count
 $bucket.LowerBound = $Histogram.Item($i).LowerBound
 $bucket.UpperBound = $Histogram.Item($i).UpperBound
 $bucket.Width = $Histogram.Item($i).Width
 $bucket
 }
 }

#Example using the function:
 Get-Bucket -Histogram $hist | Format-Table -AutoSize

Probability Distributions

# Create a parameterized instance and show its distribution properties:
$gamma = New-Object -TypeName MathNet.Numerics.Distributions.Gamma -ArgumentList 2.0,1.5
$gamma

# Distribution functions:
 [Double] $a = $gamma.Density(2.3) # PDF
 [Double] $b = $gamma.DensityLn(2.3) # ln(PDF)
 [Double] $c = $gamma.CumulativeDistribution(0.7) # CDF

# Fill an array:
 [Double[]] $data = 1..1000
 $gamma.Samples($data)

Special Functions and Trigonometry

# Special Functions and the [FUNC] accelerator (see above on accelerators):
[MathNet.Numerics.SpecialFunctions]::Factorial(13)
[MathNet.Numerics.SpecialFunctions]::FactorialLn(31) #Log
[MathNet.Numerics.SpecialFunctions]::Binomial(15,7)
[MathNet.Numerics.SpecialFunctions]::BinomialLn(15,7) #Log
[MathNet.Numerics.SpecialFunctions]::Gamma(33)
[MathNet.Numerics.SpecialFunctions]::GammaLn(33) #Log

# Create an accelerator shortcut [FUNC] for use of MathNet.Numerics.SpecialFunctions:
 [psobject].Assembly.GetType("System.Management.Automation.TypeAccelerators")::Add('FUNC','MathNet.Numerics.SpecialFunctions')

[FUNC]::ExponentialIntegral(17,4)
 [FUNC]::Beta(17,2)
 [FUNC]::Erf(0.9)
 [FUNC]::Harmonic(37)

# Trigonometry
 [MathNet.Numerics.Trig]::Cos(36)
 [MathNet.Numerics.Trig]::Tan(12)
 [MathNet.Numerics.Trig]::DegreeToRadian(360)

Euclid and Number Theory

[MathNet.Numerics.Euclid]::GreatestCommonDivisor(99,33)
[MathNet.Numerics.Euclid]::LeastCommonMultiple(3,5,6)
[MathNet.Numerics.Euclid]::IsPowerOfTwo(1024)
[MathNet.Numerics.Euclid]::Remainder(7,3)
[MathNet.Numerics.Euclid]::Modulus(-5,3)

Curve Fitting: Linear Regression

# Compute intercept and slope using least squares fit:
[Double[]] $xdata = @(10,20,30,40,50)
[Double[]] $ydata = @(15,25,35,45,55)
$Line = [MathNet.Numerics.Fit]::Line($xdata, $ydata)
$Line.Item1 #Intercept
$Line.Item2 #Slope

# Compute coefficient of determination:
 [MathNet.Numerics.GoodnessOfFit]::RSquared($xdata, $ydata)

# Polynomial regression of order 3:
 [MathNet.Numerics.Fit]::Polynomial($xdata,$ydata,3)

# Multiple regression with QR decomposition:
 [Double[][]] $xy = @( [Double[]]@(1,4), [Double[]]@(2,5), [Double[]]@(3,2) )
 [Double[]] $z = @(15,20,10)
 $QR = [MathNet.Numerics.LinearRegression.DirectRegressionMethod]::QR
 [MathNet.Numerics.Fit]::MultiDim( $xy, $z, $true, $QR )

Loading and Saving Data

# Load the MathNet.Numerics.Data.Text DLL before calling the functions:
Add-Type -Path .\MathNet.Numerics.Data.Text.dll

# Function to save a matrix to a file, and download the script to see proper formatting:
 # (Defaults to tab-delimited Double[] data with no column headers.)
 Function Export-MatrixToFile
 {
 [CmdletBinding()] Param
 (
 [Parameter(Mandatory = $true)] $FilePath,
 [Parameter(Mandatory = $true)] $Matrix,
 $DataType = "Double",
 $Delimeter = "`t",
 $ColumnHeaders = $Null,
 $Format = $Null,
 $FormatProvider = $Null,
 $MissingValue = $Null
 )

#If $FilePath is not explicit, assume present working directory:
 if ( ($FilePath -like '.\*') -or ($FilePath -notlike '*\*'))
 { $FilePath = "$pwd\$FilePath" }

$Methods = [MathNet.Numerics.Data.Text.DelimitedWriter].GetMethods() | Where { $_.IsStatic -and $_.IsPublic -and $_.Name -eq 'Write' }

ForEach ($Method in $Methods)
 {
 if ($Method.GetParameters() | Where {$_.Name -eq 'filePath'})
 {
 $Generic = $Method.MakeGenericMethod($DataType)
 $Generic.Invoke( [MathNet.Numerics.Data.Text.DelimitedWriter], @($FilePath, $Matrix, $Delimeter, $ColumnHeaders, $Format, $FormatProvider, $MissingValue))
 Return
 }
 }
 }


# Example of calling the function:
 $Matrix = [MathNet.Numerics.LinearAlgebra.Matrix[Double]]::Build.Random(500,500)
 Export-MatrixToFile -FilePath "output.tsv" -Matrix $matrix

# Function to load a matrix from a file:
 # (Defaults to tab-delimited Double[] data with no column headers.)
 Function Import-MatrixFromFile
 {
 [CmdletBinding()] Param
 (
 [Parameter(Mandatory = $true)] $FilePath,
 $DataType = "Double",
 $Sparse = $false,
 $Delimeter = "`t",
 $HasHeaders = $false,
 $FormatProvider = $Null,
 $MissingValue = $Null
 )

#Get full path to $FilePath
 $FilePath = @(dir $FilePath)[0].FullName

$Methods = [MathNet.Numerics.Data.Text.DelimitedReader].GetMethods() | Where { $_.IsStatic -and $_.IsPublic -and $_.Name -eq 'Read' }

ForEach ($Method in $Methods)
 {
 if ($Method.GetParameters() | Where {$_.Name -eq 'filePath'})
 {
 $Generic = $Method.MakeGenericMethod($DataType)
 $Generic.Invoke( [MathNet.Numerics.Data.Text.DelimitedReader], @($FilePath, $Sparse, $Delimeter, $HasHeaders, $FormatProvider, $MissingValue))
 Return
 }
 }
 }

# Example of calling the function:
 Import-MatrixFromFile -FilePath "output.tsv"

NIST Matrix Market Text Files

# Load the MathNet.Numerics.Data.Text DLL:
Add-Type -Path .\MathNet.Numerics.Data.Text.dll

# Function to load a NIST Matrix Market file:
 # (Defaults to uncompressed, matrix of Double[], not vectors.)
 Function Import-NistMatrixMarketFile
 {
 [CmdletBinding()] Param
 (
 [Parameter(Mandatory = $true)] $FilePath,
 $DataType = "Double",
 [Switch] $IsVector,
 [Switch] $IsCompressed
 )

#Assume file contains a matrix
 if ($IsVector){$Name = 'ReadVector'} else {$Name = 'ReadMatrix'}

#Assume file is not compressed
 if ($IsCompressed){ $Compression = [MathNet.Numerics.Data.Text.Compression]::GZip }
 else { $Compression = [MathNet.Numerics.Data.Text.Compression]::Uncompressed }

#Get full path to $FilePath
 $FilePath = @(dir $FilePath)[0].FullName

$Methods = [MathNet.Numerics.Data.Text.MatrixMarketReader].GetMethods() | Where { $_.IsStatic -and $_.IsPublic -and $_.Name -eq $Name }

ForEach ($Method in $Methods)
 {
 if ($Method.GetParameters() | Where {$_.Name -eq 'filePath'})
 {
 $Generic = $Method.MakeGenericMethod($DataType)
 $Generic.Invoke( [MathNet.Numerics.Data.Text.MatrixMarketReader], @($FilePath, $Compression))
 Return
 }
 }
 }

# Example of calling the function:
 Import-NistMatrixMarketFile -FilePath "matrixmarket.mtx"

# Function to save a NIST Matrix Market file:
 # (Defaults to matrix of Double[], not vector.)
 Function Export-NistMatrixMarketFile
 {
 [CmdletBinding()] Param
 (
 [Parameter(Mandatory = $true)] $FilePath,
 [Parameter(Mandatory = $true)] $Matrix,
 $DataType = "Double",
 [Switch] $IsVector,
 [Switch] $IsCompressed
 )

#Assume file will contain a matrix
 if ($IsVector){$Name = 'WriteVector'} else {$Name = 'WriteMatrix'}

#Assume file is not compressed
 if ($IsCompressed){ $Compression = [MathNet.Numerics.Data.Text.Compression]::GZip }
 else { $Compression = [MathNet.Numerics.Data.Text.Compression]::Uncompressed }

#If $FilePath is not explicit, assume present working directory:
 if ( ($FilePath -like '.\*') -or ($FilePath -notlike '*\*'))
 { $FilePath = "$pwd\$FilePath" }

$Methods = [MathNet.Numerics.Data.Text.MatrixMarketWriter].GetMethods() | Where { $_.IsStatic -and $_.IsPublic -and $_.Name -eq $Name }

ForEach ($Method in $Methods)
 {
 if ($Method.GetParameters() | Where {$_.Name -eq 'filePath'})
 {
 $Generic = $Method.MakeGenericMethod($DataType)
 $Generic.Invoke( [MathNet.Numerics.Data.Text.MatrixMarketWriter], @($FilePath, $Matrix, $Compression))
 Return
 }
 }
 }

# Examples of calling the function:
 $Matrix = [MathNet.Numerics.LinearAlgebra.Matrix[Double]]::Build.Random(500,500)
 Export-NistMatrixMarketFile -FilePath "matrixmarket2.mtx" -Matrix $Matrix

$Vector = [MathNet.Numerics.LinearAlgebra.Vector[Double]]::Build.Random(1000)
 Export-NistMatrixMarketFile -FilePath "matrixmarket3.mtx" -Matrix $Vector -IsVector

Loading and Saving Data Using PowerShell Cmdlets

# Create a matrix to save and restore and add the [M] accelerator:
$OriginalMatrix = [MathNet.Numerics.LinearAlgebra.Matrix[Double]]::Build.Random(5000,5000)
[psobject].Assembly.GetType("System.Management.Automation.TypeAccelerators")::Add('M','MathNet.Numerics.LinearAlgebra.Matrix[Double]')

# Save as XML with UTF-8 encoding to reduce file size (creates a 1GB file):
 $OriginalMatrix | Export-Clixml -Encoding UTF8 -Path .\Matrix-5000x5000.xml

# Restore the original matrix from XML using accelerator:
 [Double[]] $RestoredValues = (Import-Clixml -Path .\Matrix-5000x5000.xml).Values
 $RestoredMatrix = [M]::Build.DenseOfColumnMajor(5000,5000,$RestoredValues)
 

Remember, too, that data can simply be saved to a CSV text file (using Export-Csv) and then opened directly in Excel.

Update History

26.Jun.2015: Original.
28.Jun.2015: Added functions for importing/exporting data.
29.Jun.2015: Added some Intel MKL performance test results.
22.May.2016: Updated test results for PoSh 5.0 and latest Intel MKL version.