[ksa]

Такой еще вариант предложу...

var matrix4D = [
  [1, 1, 1, 1],
  [1, 1, 1, 1],
  [1, 1, 1, 1],
  [1, 1, 1, 1]
];
var matrix4_D = [
  [1, 1, 1, 3],
  [1, 1, 6, 1],
  [1, 2, 1, 10],
  [9, 1, 1, 1],
  [1, 1, 11, 1]
];
var matrix5D = [
  [1, 2, 3, 4, 5],
  [1, 1, 1, 3, 4],
  [1, 1, 1, 1, 1]
];
alert(function_matrix(matrix4D));
alert(function_matrix(matrix4_D));
alert(function_matrix(matrix5D));
function function_matrix(arr){
    var col = arr[0].length;
	var row = 0;
    var res = [];
	while ((col > -1) && (row < arr.length)) {
        res.push(arr[row++][--col]);
    }
    return res
};