module.exports = function (math) { var util = require('../../util/index.js'), Complex = require('../../type/Complex.js'), collection = require('../../type/collection.js'), isNumBool = util.number.isNumBool, isComplex = Complex.isComplex, isCollection = collection.isCollection; /** * Calculate the square root of a value * * sqrt(x) * * For matrices, the function is evaluated element wise. * * @param {Number | Boolean | Complex | Array | Matrix} x * @return {Number | Complex | Array | Matrix} res */ math.sqrt = function sqrt (x) { if (arguments.length != 1) { throw new util.error.ArgumentsError('sqrt', arguments.length, 1); } if (isNumBool(x)) { if (x >= 0) { return Math.sqrt(x); } else { return sqrt(new Complex(x, 0)); } } if (isComplex(x)) { var r = Math.sqrt(x.re * x.re + x.im * x.im); if (x.im >= 0) { return new Complex( 0.5 * Math.sqrt(2.0 * (r + x.re)), 0.5 * Math.sqrt(2.0 * (r - x.re)) ); } else { return new Complex( 0.5 * Math.sqrt(2.0 * (r + x.re)), -0.5 * Math.sqrt(2.0 * (r - x.re)) ); } } if (isCollection(x)) { return collection.deepMap(x, sqrt); } if (x.valueOf() !== x) { // fallback on the objects primitive value return sqrt(x.valueOf()); } throw new util.error.UnsupportedTypeError('sqrt', x); }; };