matscript

MatScript

MatScript is a Node.js package that can compile a subset of Matlab/Octave to JavaScript. This subset excludes data types such as structures and cells, classes, but also strings (why would you prefer doing string manipulations in Matlab rather than JavaScript).

Its current state is just a proof of concept. The core library allows the addition, multiplication and transposition of matrices. The next release should bring along the inclusion of a bigger, third-party library.

The compiler itself needs a lot of attention, too. While it currently accepts Matlab code (as far as implemented; indexing is one important feature still missing), it will not always reject invalid code. Contributions to its development are of course welcome.

Installation

$ npm install matscript

Compiling .m function files

Let's walk through the steps of compiling the file f.m containing the following function definition:

function Y = f(X)
    Y = X * X';
end

To use this function in your Node.js project with MatScrip installed, follow these steps:

• Create the directories ./src and ./dist in your project root if these do not yet exist
• Copy f.m into in the ./src directory
• Command $ msc

The following module will be created and saved as f.js in the /dist folder:

import { Matrix, sum, prod, transpose } from '../node_modules/matscript/lib/core/Matrix.js'
import { Fun } from '../node_modules/matscript/lib/core/Fun.js'

export function f( X ) {

let Y;

Y = prod([X, transpose(X)]);

return Y;

};

Use the function like this:

import { f } from './dist/f.js'

console.log(f(3))

Of course, in this example the output will just be the scalar 9. The following sections explain how to call functions on matrix arguments.

Core library

The core library for matrix computations is limited to provide a Matrix class together with the functions sum(), prod() and tanspose(). One way to use functions with matrix arguments is by importing this Matrix class:

import { Matrix } from './node_modules/matscript/lib/core/Matrix.js'

let A = new Matrix([[1, 2],[3, 4]])

Interpreter

You can also import an interpreter to embed Matlab code directly in your JavaScript files:

import { f } from './dist/f.js'
import { interpret } from './node_modules/matscript/lib/compiler/compiler.js'

let A = interpret("[1 2; 3 4];");

console.log(f(A))