iainnz/simplexjs

A linear and mixed-integer linear programming solver written in Javascript.

simplexjs's Issues

Help with API

Cool project but how would I use it to solve this problem?

Maximize, z = x1 + 2x2 - x3

Constraints:
2x1 + 2x2 + x3 <= 14
4x1 + 2x2 + 3x3 <= 28
2x1 + 5x2 + 5x3 <= 30

0 <= x1, 0 <= x2, 0 <= x3

PrimalSimplex outputs infeasible, while there should be a solution

First of all: great work.

I want to solve a maximal matching in a bipartite graph.
Therefore I model A as the incidencematrix of the graph. In some cases this works pretty good. But there is a setup where a solution exists but your implementation does not find it.
The special structure of the problem is that there is on one on one side who has connections to all nodes on the other side. (Example below with 4 nodes, but also tested with 3 nodes)
Possible solutions will be (1,0,0) or (0,1,0) or (0,0,1)

var test = new Object();
    test.A = [[1, 0, 0],
              [1, 0, 0],
              [0, 1, 0],
              [1, 1, 1]];
    test.b = [1, 1, 1, 1];
    test.c = [1, 1, 1];
    test.m = 4;
    test.n = 3;
    test.xLB = [0, 0, 0];
    test.xUB = [Infinity, Infinity, Infinity];

Can you verify if the problem exists in your implementation or in my modelling?

How to use?

I've been trying to figure out how to use this project. I looked at the TestSimplexJS.js though didn't really understand. You use variables A, b, c, m, n without explanation what they are. (I assume xLB en xUB are lower and upper bound.)

This would be the first time I use a linear solver, so perhaps I'm just missing something obvious. Could you explain what is what a little more?

Thanks a lot!