@rayyamhk/matrix/lib/core/properties/cond.js

A professional, comprehensive and high-performance library for you to manipulate matrices.

"use strict";

var Matrix = require('../..');

var _require = require('../../Error'),
    INVALID_P_NORM = _require.INVALID_P_NORM,
    SINGULAR_MATRIX = _require.SINGULAR_MATRIX,
    INVALID_SQUARE_MATRIX = _require.INVALID_SQUARE_MATRIX;
/**
 * Calculations the condition number of square Matrix
 * with respect to the choice of Matrix norm. 
 * If the Matrix is singular, returns Infinity.<br><br>
 * The condition number is not cached.
 * @memberof Matrix
 * @instance
 * @param {(1|2|Infinity|'F')} p - Type of Matrix norm
 * @returns {number} The condition number of Matrix
 */


function cond() {
  var p = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 2;

  if (p !== 1 && p !== 2 && p !== Infinity && p !== 'F') {
    throw new Error(INVALID_P_NORM);
  }

  if (!this.isSquare()) {
    throw new Error(INVALID_SQUARE_MATRIX);
  }

  try {
    var inverse = Matrix.inverse(this);
    return inverse.norm(p) * this.norm(p);
  } catch (error) {
    if (error.message === SINGULAR_MATRIX) {
      return Infinity;
    }

    throw error;
  }
}

;
module.exports = cond;