我想在 Python 中重载乘法运算符。我真正想做的是将 4x4 矩阵与 4D 向量相乘。
import math
class Vec4():
def __init__(self, x = 0, y = 0, z = 0, w = 0):
"""Constructor for Vec4
DO NOT MODIFY THIS METHOD"""
self.values = [x,y,z,w]
def __str__(self):
"""Returns the vector as a string representation
DO NOT MODIFY THIS METHOD"""
toReturn = ''
if self is None: return '0.00 0.00 0.00 0.00'
for c in range(0,4):
toReturn += "%.2f" % self.values[c]
if c != 3:
toReturn += ' '
return toReturn
class Matrix4():
def __init__(self, row1=None, row2=None, row3=None, row4=None):
"""Constructor for Matrix4
DO NOT MODIFY THIS METHOD"""
if row1 is None: row1 = Vec4()
if row2 is None: row2 = Vec4()
if row3 is None: row3 = Vec4()
if row4 is None: row4 = Vec4()
self.m_values = [row1,row2,row3,row4]
def __str__(self):
"""Returns a string representation of the matrix
DO NOT MODIFY THIS METHOD"""
toReturn = ''
if self is None: return '0.00 0.00 0.00 0.00\n0.00 0.00 0.00 0.00\n0.00 0.00 0.00 0.00\n0.00 0.00 0.00 0.00'
for r in range(0,4):
for c in range(0,4):
toReturn += "%.2f" % self.m_values[r].values[c]
if c != 3:
toReturn += ' '
toReturn += '\n'
return toReturn
def __mul__(self, v):
"""Element wise multiplication of self by vector v
Returns the result as a new vector"""
x = self.m_values[0][0]*self.values[0]+self.m_values[0][1]*self.values[1]+self.m_values[0][2]*self.values[2]+self.m_values[0][3]*self.values[3]
y = self.m_values[1][0]*self.values[0]+self.m_values[1][1]*self.values[1]+self.m_values[1][2]*self.values[2]+self.m_values[1][3]*self.values[3]
z = self.m_values[2][0]*self.values[0]+self.m_values[2][1]*self.values[1]+self.m_values[2][2]*self.values[2]+self.m_values[3][3]*self.values[3]
w = self.m_values[3][0]*self.values[0]+self.m_values[3][1]*self.values[1]+self.m_values[3][2]*self.values[2]+self.m_values[3][3]*self.values[3]
return Vec4(x,y,z,w)
如您所见,我已经尝试实现它。它对我不起作用。结果应该是一个向量。
A = Matrix4(Vec4(1, 0, 0, 0),
Vec4(0, 1, 0, 0),
Vec4(0, 0, 1, 0),
Vec4(0, 0, 0, 1))
>>> V = Vec4(1,2,3,4)
>>> print(A*V)
结果应为“1.00 2.00 3.00 4.00”。
但这会导致错误:
Traceback (most recent call last):
File "<pyshell#27>", line 1, in <module>
print(A*V)
File "C:\Users\xxx\Downloads\Download-Stuff\Gmail\TransformMatrix.py", line 45, in __mul__
x = self.m_values[0].values[0]*self.values[0]+self.m_values[0].values[1]*self.values[1]+self.m_values[0].values[2]*self.values[2]+self.m_values[0].values[3]*self.values[3]
AttributeError: 'Matrix4' object has no attribute 'values'
我应该怎么办?我究竟做错了什么?有人告诉我使用嵌套循环,但我不熟悉它。
请帮我!
提前致谢!