emlapack

Porting BLAS / LAPACK to JavaScript.

CLAPACK is compiled with emscripten.

Install

``
npm install emlapack
`

Example

Computing all eigenvalues of a real (upper triangular) symmetric matrix A

`javascript
var emlapack = require('emlapack'),
n = 5,
dsyev = emlapack.cwrap('dsyev_', null, ['number', 'number', 'number', 'number', 'number', 'number', 'number', 'number', 'number']),
pjobz = emlapack._malloc(1),
puplo = emlapack._malloc(1),
pn = emlapack._malloc(4),
pa = emlapack._malloc(n n 8),
plda = emlapack._malloc(4),
pw = emlapack._malloc(n * 8),
plwork = emlapack._malloc(4),
pinfo = emlapack._malloc(4),
pworkopt = emlapack._malloc(4);

emlapack.setValue(pjobz, 'V'.charCodeAt(0), 'i8');
emlapack.setValue(puplo, 'U'.charCodeAt(0), 'i8');
emlapack.setValue(pn, n, 'i32');
emlapack.setValue(plda, n, 'i32');
emlapack.setValue(plwork, -1, 'i32');

var a = new Float64Array(emlapack.HEAPF64.buffer, pa, n * n);
var w = new Float64Array(emlapack.HEAPF64.buffer, pw, n);
a.set([1.96, 0, 0, 0, 0, -6.49, 3.8, 0, 0, 0, -0.47, -6.39, 4.17, 0, 0, -7.2, 1.5, -1.51, 5.7, 0, -0.65, -6.34, 2.67, 1.8, -7.1]);

dsyev(pjobz, puplo, pn, pa, plda, pw, pworkopt, plwork, pinfo);

var workopt = emlapack.getValue(pworkopt, 'double'),
pwork = emlapack._malloc(workopt * 8);
emlapack.setValue(plwork, workopt, 'i32');

dsyev(pjobz, puplo, pn, pa, plda, pw, pwork, plwork, pinfo);

console.log(w);
// { '0': -11.065575263268391,
// '1': -6.22874693239854,
// '2': 0.8640279752720624,
// '3': 8.865457108365518,
// '4': 16.09483711202934 }
`

Building

To build, you'll need to install and set up Emscripten, then download clapack into ./clapack.

First, configure clapack by creating make.inc:

`bash
$ cd clapack
$ cp make.inc.example make.inc
`

Next, follow the libf2c installation instructions. You'll need to tell it to create .h from .h0 files. The easiest way is to just make all:

`bash
$ cd F2CLIBS/libf2c
$ make all
`

Now from the main emlapack directory, proceed with gulp build:

`bash
$ gulp build
`

This should take a while. Coffee, perhaps?

Customizing Builds

If the bundle is too large and you know the specific set of functions you would like to use, you can create a file called custom/export-functions.js with the specific functions you want to create a bundle specific to your requirements. In the custom folder you can see files ending in .example.js to help you get started.

Docker

For convenience, this repo also includes a Dockerfile so you can build everything in Docker.

`shell
./scripts/docker_build.sh
``

For more detail, see:

* http://www.netlib.org/blas/
* http://www.netlib.org/lapack/
* http://emscripten.org/

License

© 2015 Yosuke Onoue, BSD-3-Clause.