Integrate .NET Assembly into F# Application

The F# programming language offers the opportunity to implement the same solutions you usually implement using C#, but with less code. This can be helpful when scaling a deployment solution across an enterprise-wide installation, or in any situation where code efficiency is valued. The brevity of F# programs can also make them easier to maintain.

The following example shows you how to integrate the deployable MATLAB^® magic function into an F# application.

Prerequisites

You must be running Microsoft^® Visual Studio^® 2010 or higher to use this example.

If you build this example on a system running 64-bit Microsoft Visual Studio, you must add a reference to the 32-bit MWArray DLL due to a current imitation of Microsoft's F# compiler.

Step 1: Build the Component

Build the MagicSquareComp component using the instructions in Generate .NET Assembly and Build .NET Application.

Step 2: Integrate Component Into F# Application

Using Microsoft Visual Studio 2010 or higher, create an F# project.
Add references to your .NET component and MWArray in Visual Studio.
Make the .NET namespaces available for your component and MWArray libraries:
```
open MagicSquareComp
open MathWorks.MATLAB.NET.Arrays
```

Define the Magic Square function with an initial let statement, as follows:

let magic n =

Then, add the following statements to complete the function definition.

Instantiate the Magic Square component:

use magicComp = new MagicSquareComp.MagicSquareClass()

Define the input argument:

use inarg = new MWNumericArray((int) n)

Call MATLAB, get the output argument cell array, and extract the first element as a two–dimensional float array:
```
(magicComp.makesquare(1, inarg).[0].ToArray() :?> float[,])
```

The complete function definition looks like this:

let magic n =
    // Instantiate the magic square component
    use magicComp = new MagicSquareComp.MagicSquareClass()
    // Define the input argument
    use inarg = new MWNumericArray((int) n)
    // Call MATLAB, get the output argument cell array,
    // extract the first element as a 2D float array
    (magicComp.makesquare(1, inarg).[0].ToArray() 
                                     :?> float[,])

Add another let statement to define the output display logic:

let printMagic n = 
  let numArray = magic n
  // Display the output
  printfn "Number of [rows,cols]: [%d,%d]" 
      (numArray.GetLength(0)) (numArray.GetLength(1))
  printfn ""
  for i in 0 .. numArray.GetLength(0)-1 do
    for j in 0 .. numArray.GetLength(1)-1 do
      printf "%3.0f " numArray.[i,j]
    printfn ""
  printfn "=========================\n"

ignore(List.iter printMagic [1..19])
// Pause until keypress
ignore(System.Console.ReadKey())

The complete program listing follows:

The F# Magic Square Program

Step 3: Deploy the Component

For information about deploying your component to end users, see MATLAB Runtime.