| 46 | return self + other * -1 |
| 47 | |
| 48 | def __mul__(self, other): |
| 49 | if not isinstance(other, Dual): |
| 50 | new_duals = [] |
| 51 | for i in self.duals: |
| 52 | new_duals.append(i * other) |
| 53 | return Dual(self.real * other, new_duals) |
| 54 | new_duals = [0] * (len(self.duals) + len(other.duals) + 1) |
| 55 | for i, item in enumerate(self.duals): |
| 56 | for j, jtem in enumerate(other.duals): |
| 57 | new_duals[i + j + 1] += item * jtem |
| 58 | for k in range(len(self.duals)): |
| 59 | new_duals[k] += self.duals[k] * other.real |
| 60 | for index in range(len(other.duals)): |
| 61 | new_duals[index] += other.duals[index] * self.real |
| 62 | return Dual(self.real * other.real, new_duals) |
| 63 | |
| 64 | __rmul__ = __mul__ |
| 65 | |