js-solver

js-solver

algebraic equation solving helper library

include

//node.js
npm install js-solver
var Solver = require('js-solver')
//browser
<script src='js-solver.js'></script>

usage

var mySolver = new Solver({
  a: 'b+c',
  b: 'a-c',
  c: 'a-c'
})

mySolver.solve({
  b: 2,
  c: 3
})
/* solved for 'a' based on equation
  {
    a:5, b:2, c:3
  }
*/

more in depth example

var triangleSolver = new Solver({
    area: 'base*h/2',
    c: 'Math.sqrt(Math.pow(a,2)+Math.pow(b,2)) || base/2', //base/2 is an example of a dual-equation definition
    a: 'Math.sqrt(Math.pow(c,2)-Math.pow(b,2))',
    b: 'Math.sqrt(Math.pow(c,2)-Math.pow(a,2))',
    h: 'area*2/base',
    base: 'area*2/h'
})
triangleSolver.solve({
    c: 5,
    b: 3,
    area: 50,
    h: 10
})
/*
  { c: 5, b: 3, area: 50, h: 10, a: 4, base: 10 }
*/

Bonus

These are also valid equations

'a^2+b^2' //^ == power
'sqrt(c**2-a**2)' //** == power - from python, also notice sqrt, without the Math. in front (see note)

Valid Math defaults:

abs acos asin atan atan2 ceil co exp floor log pow E PI sin sqrt tan

notes:

The equations are evaled, so be aware of that. Also I used with(Math) to get the math stuff to eval... yeah...