Question

所以我有这个乘法矩阵的代码，但它只适用于2x2矩阵。我没有那种编程经验，所以我不知道我做错了什么。谁能告诉我这个代码如何用于乘以3x3矩阵？我如何管理结果写成矩阵而不只是一行？有没有比document.write（mResult）更好的方法;？

＆＃13;

function multiply(m1, m2) {
  var result = [];
  for (var i = 0; i < m1.length; i++) {
    result[i] = [];
    for (var j = 0; j < m2[0].length; j++) {
      var sum = 0;
      for (var k = 0; k < m1[0].length; k++) {
        sum += m1[i][k] * m2[k][j];
      }
      result[i][j] = sum;
    }
  }
  return result;
}

var m1 = [
  [1, 2],
  [3, 8]
];
var m2 = [
  [5, 9],
  [7, 1]
];
var mResult = multiply(m1, m2);
document.write(mResult);

＆＃13;

Answer 1

这应该有效：

function multiply (a, b) {
  const transpose = (a) => a[0].map((x, i) => a.map((y) => y[i]));
  const dotproduct = (a, b) => a.map((x, i) => a[i] * b[i]).reduce((m, n) => m + n);
  const result = (a, b) => a.map((x) => transpose(b).map((y) => dotproduct(x, y)));
  return result(a, b);
}

在javascript中乘以3x3矩阵

1 个答案: