@rayyamhk/matrix/lib/util/isMatrix.js

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

"use strict";

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

module.exports = function isMatrix(matrix) {
  if (!Array.isArray(matrix)) {
    return false;
  }

  var height = matrix.length;

  if (height === 0) {
    return true; // [] represents empty matrix (0 x 0 matrix)
  }

  var firstRow = matrix[0];

  if (!Array.isArray(firstRow)) {
    return false;
  }

  var width = firstRow.length;

  if (width === 0) {
    return false; // [ [] ] is not allowed
  }

  for (var i = 0; i < height; i++) {
    var row = matrix[i];

    if (!Array.isArray(row) || row.length !== width) {
      return false;
    }

    for (var j = 0; j < width; j++) {
      if (!isNumber(row[j])) {
        return false;
      }
    }
  }

  return true;
};