Kaid's Blog

Tutorial for Column Wise Multiplication of Two matrix by lists in python suppose we want to multiply two lists of different lengths in python how to do it? Well there are many ways of Doing it from itertools we can use map but it multiples lists of equal length only using numpy but creating numpy arrays are not so useful it includes complicated stuff here ill show you  can do it simply using logic Suppose i have a 2d array and i want to multiply it column wise [ 1 2 3  ]     [1]     [1, 4, 7] [  4 5 6 ] *  [2] =  [2, 5, 8] [  7 8 9 ]     [3]     [3, 6, 9] So in python we create a list inside a list a=[[1,2,3],[4,5,6],[7,8,9]] b=[1,2,3] for row in range(len(a)): print([a[col][row] for col in range(len(b)) ]) [1, 4, 7] [2, 5, 8] [3, 6, 9] mul=[[1, 2, 3, 4, 0, 0], [0, 1, 2, 3, 4, 0], [0, 0, 1, 2, 3, 4], [4, 0, 0, 1, 2, 3], [3, 4, 0, 0, 1, 2], [2, 3, 4, 0, 0, 1]] hn=[-3, 2, 1, 0, 0, 0] so the ans should be [[-3, 0, 0, 0, 0, 0], [-6, 2, 0, 0, 0, 0], [-