ValueError could not broadcast input array from shape 4 1 into shape 4

Question

This code produces this error of broadcasting and I don't understand why. N is a number, C is a matrix 4x4, xvec_tra an array 4x1 and the result x should be a matrix 4xN.

x=np.zeros(shape=(4,int(N)), dtype=np.float64)
for i in range(0, int(N/2)):
    if i == 0:   
        x[:,0]=C * xvec_tra
        print(x[:,0])
else:
    x[:,i]=C*x[:,i-1]
    print(x[:,i])

Answer 1

Hey @Giorgio,

You can try this hope this will resolve your error.

import numpy as np

N=0

C=0

x=np.zeros(shape=(4,int(N)), dtype=np.float64)

for i in range(0, int(N/2)):

    if i == 0:   

        x[:,0]=C * xvec_tra

        print(x[:,0])

    else:

      x[:,i]=C*x[:,i-1]

      print(x[:,i])

print(N)