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

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:

$ 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:

$ cd F2CLIBS/libf2c
$ make all

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

$ gulp build

This should take a while. Coffee, perhaps?

For more detail, see:

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

License

© 2015 Yosuke Onoue, BSD-3-Clause.