@rayyamhk/matrix/lib/core/structure/isDiagonal.js

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

"use strict";

function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _unsupportedIterableToArray(arr, i) || _nonIterableRest(); }

function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); }

function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(o); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); }

function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) { arr2[i] = arr[i]; } return arr2; }

function _iterableToArrayLimit(arr, i) { var _i = arr == null ? null : typeof Symbol !== "undefined" && arr[Symbol.iterator] || arr["@@iterator"]; if (_i == null) return; var _arr = []; var _n = true; var _d = false; var _s, _e; try { for (_i = _i.call(arr); !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; }

function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }

/**
 * Determines whether a Matrix is diagonal or not.<br><br>
 * 
 * Diagonal Matrix is a Matrix in which the entries outside the main diagonal
 * are all zero. Note that the term diagonal refers to rectangular diagonal.<br><br>
 * 
 * The result is cached.
 * @memberof Matrix
 * @instance
 * @param {number} [digit=8] - Number of significant digits
 * @returns {boolean} Returns rue if the Matrix is diagonal Matrix
 */
function isDiagonal() {
  var digit = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : this._digit;

  if (this._isDiagonal !== undefined) {
    return this._isDiagonal;
  }

  var EPSILON = 1 / (Math.pow(10, digit) * 2);
  var A = this._matrix;

  var _this$size = this.size(),
      _this$size2 = _slicedToArray(_this$size, 2),
      row = _this$size2[0],
      col = _this$size2[1];

  if (row === 0) {
    this._isDiagonal = true;
    return true;
  }

  for (var i = 0; i < row; i++) {
    for (var j = 0; j < col; j++) {
      if (i !== j && Math.abs(A[i][j]) >= EPSILON) {
        this.isDiagonal = false;
        return false;
      }
    }
  }

  this._isDiagonal = true;
  return true;
}

;
module.exports = isDiagonal;