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a=np.array([[1,2],[3,4]])print(a.shape)b=np.array([[[7,8],[8,9]], [[7,8],[8,9]]])print(b.shape)print(b-a,(b-a).shape)print('==============11111===============')a=np.array([[1,2],[3,4]])print(a.shape)b=np.array([[[[7,8],[8,9]]]])print(b.shape)print(b-a,(b-a).shape)print('==============22222===============')#最后一个维度的元素数分别为2和3,报错a=np.array([[1,2,3],[3,4,5]])print(a.shape)b=np.array([[[7,8],[8,9]], [[7,8],[8,9]]])print(b.shape)try: print(b-a,(b-a).shape)except Exception as e: print(e)print('=============33333================')#其中一个矩阵的最后一个维度元素数为1,不报错a=np.array([[1],[3]])print(a.shape)b=np.array([[[7,8,9,10],[8,9,10,11]]])print(b.shape)try: print(b-a,(b-a).shape)except Exception as e: print(e)print('============44444=================')#其中一个矩阵的最后一个维度元素数为1,不报错a=np.array([[1,2,3],[3,4,5]])print(a.shape)b=np.array([[[7],[8]]])print(b.shape)try: print(b-a,(b-a).shape)except Exception as e: print(e)print('============55555=================')#最后一个维度的元素数分别为4和2,报错a=np.array([[1,2],[3,4]])print(a.shape)b=np.array([[[7,8,9,10],[8,9,10,11]]])print(b.shape)try: print(b-a,(b-a).shape)except Exception as e: print(e)print('============66666=================')
输出:
当两个矩阵最后一个维度元素数相同时,加减完后矩阵的形状和高维矩阵的相同;当不同时(其中一个矩阵的最后一维元素数为1),矩阵维度和高维度矩阵相同,但最后一维的元素数和原来两个矩阵中最后一维元素数较多的矩阵相同。
a=np.array([[1,2,3],[4,5,6]])b=np.array([[1,2],[2,3]])try: print(a*b,(b-a).shape)except Exception as e: print(e)print('============11111============')a=np.array([[1,2,3],[4,5,6]])b=np.array([1,2])try: print(a*b,(b-a).shape)except Exception as e: print(e)print('============22222============')a=np.array([[1,2,3,4],[4,5,6,7]])b=np.array([1,2])try: print(a*b,(b-a).shape)except Exception as e: print(e)print('============33333============')a=np.array([[1,2,3,4],[4,5,6,7]])b=np.array([2])try: print(a*b,(b-a).shape)except Exception as e: print(e)print('============44444============')a=np.array([[1,1,1,1],[2,2,2,2]])b=np.array([[2,4,6,8],[1,3,5,7]])try: print(a*b,(b-a).shape)except Exception as e: print(e)print('============55555============')
输出:
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