glpk.js

glpk.js

JavaScript/WebAssembly port of GLPK (GNU Linear Programming Kit) for browser & node. Rather than porting the complete GLPK library (including GLPSOL) this project aims at creating a simple JSON interface to setup and solve LP/MILP with JavaScript.

Install

npm install glpk.js

Examples

Minimal live example: https://jvail.github.io/glpk.js/examples/lp.html

import GLPK from 'glpk.js';

const glpk = await GLPK();
const options = {
    msglev: glpk.GLP_MSG_ALL,
    presol: true
};
const result = await glpk.solve({
    name: 'LP',
    objective: {
        direction: glpk.GLP_MAX,
        name: 'obj',
        vars: [
            { name: 'x1', coef: 0.6 },
            { name: 'x2', coef: 0.5 }
        ]
    },
    subjectTo: [
        {
            name: 'cons1',
            vars: [
                { name: 'x1', coef: 1.0 },
                { name: 'x2', coef: 2.0 }
            ],
            bnds: { type: glpk.GLP_UP, ub: 1.0, lb: 0.0 }
        },
        {
            name: 'cons2',
            vars: [
                { name: 'x1', coef: 3.0 },
                { name: 'x2', coef: 1.0 }
            ],
            bnds: { type: glpk.GLP_UP, ub: 2.0, lb: 0.0 }
        }
    ]
}, options);

Other Examples

glpk.js and Mixed-Integer Programming with a lot of background information:

• https://observablehq.com/@tomlarkworthy/mip

Simple LP in the browser:

• https://jvail.github.io/glpk.js/examples/lp.html

Large LP with simplex callback (600x600 transportation problem):

• https://jvail.github.io/glpk.js/examples/lp-large.html

Some (slightly outdated) examples using glpk.js:

• https://jvail.github.io/dairy.js
• https://jvail.github.io/solid-dss

API

interface LP {
    name: string,
    objective: {
        direction: number,
        name: string,
        vars: { name: string, coef: number }[]
    },
    subjectTo: {
        name: string,
        vars: { name: string, coef: number }[],
        bnds: { type: number, ub: number, lb: number }
    }[],
    bounds?: {
        name: string,
        type: number,
        ub: number,
        lb: number
    }[],
    binaries?: string[],
    generals?: string[],
    options?: Options
}

Optionally the “kind of structural variable”

• continuous variable (default)
• integer variable
• binary variable

may be specified with an array of variable names:

/* integer */
lp.generals = ['x1', 'x2'];

/* binary */
lp.binaries = ['x3', 'x4'];

/* typescript node import */
import GLPK, { type LP, type Options, type Result } from 'glpk.js/node';
glpk = await GLPK()

For full TypeScript definitions, see:

• src/types.d.ts - shared types (LP, Options, Result)
• src/index.d.ts - browser async API (default export)
• src/glpk.d.ts - Node.js sync API (glpk.js/node)

Building

emsdk

Built with emsdk 4.0.x.

git clone https://github.com/jvail/glpk.js.git
cd glpk.js
git submodule update --init --recursive
npm install
source ~/emsdk/emsdk_env.sh
npm run build && npm run test

docker

Uses official docker images for emscripten/emsdk.

docker build . -t glpk.js
docker run -v $PWD:/app glpk.js