With given 2D and 1D lists, I have to dot product them. But I have to calculate them without using .dot.
For example, I want to make these lists
matrix_A = [[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11], [12, 13, 14, 15], [16, 17, 18, 19], [20, 21, 22, 23], [24, 25, 26, 27], [28, 29, 30, 31]]
vector_x = [0, 1, 2, 3]
to this output
result_list = [ 14 38 62 86 110 134 158 182]
How can I do it by only using lists(not using NumPy array and .dot) in python?
>Solution :
You could use a list comprehension with nested for loops.
matrix_A = [[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11], [12, 13, 14, 15], [16, 17, 18, 19], [20, 21, 22, 23], [24, 25, 26, 27], [28, 29, 30, 31]]
vector_x = [0, 1, 2, 3]
result_list = [sum([a*b for a,b in zip(row, vector_x)]) for row in matrix_A]
print(result_list)
Output:
[14, 38, 62, 86, 110, 134, 158, 182]