張量點積

兩個向量的點積

import numpy as np

a1 = np.array([1, 2, 3, 4, 5])
a2 = np.array([2, 3, 4, 5, 6])
a3 = np.dot(a1, a2)
print(a3)  # 70，對應位置的值相乘再相加

向量與矩陣的點積

import numpy as np

# 矩陣與向量的點積
matrix = np.array([
    [1, 2, 3, 4, 5],
    [6, 4, 3, 2, 1]
])
vetor = np.array([3, 6, 5, 2, 1])
result = np.dot(matrix, vetor)
print(result)
"""
[43 62]
"""

矩陣與矩陣的點積

import numpy as np

# 矩陣與矩陣的點積
matrix1 = np.array([
    [1, 2, 3, 4, 5],
    [6, 4, 3, 2, 1]
])
matrix2 = np.array([
    [8, 2, 3, 4, 5],
    [6, 4, 3, 2, 1],
    [6, 4, 3, 2, 1],
    [6, 4, 3, 2, 1],
    [6, 4, 3, 2, 1]
])
result = np.dot(matrix1, matrix2)  # matrix的行與 atrix的列之間的點積
print(result)
"""
[[ 92  58  45  32  19]
 [108  52  48  44  40]]
"""