ValueError: non-broadcastable output operand with shape (1640,1) doesn't match the broadcast shape (1640,4)

This error occurs when you are trying to perform a mathematical operation that cannot be broadcasted to the output shape. In this case, the output operand has shape (1640,1) but the broadcast shape is (1640,4).

To fix this error, you can reshape the output operand to match the broadcast shape using the numpy.reshape() function. For example:

import numpy as np

# create a matrix with shape (1640, 4)
a = np.ones((1640, 4))

# create an output operand with shape (1640, 1)
b = np.ones((1640, 1))

# reshape the output operand to match the broadcast shape
b = b.reshape(1640, 4)

# perform the mathematical operation
c = a + b

In this example, we reshape the output operand `b` to have shape (1640, 4) using the `reshape()` function. Now, we can perform the mathematical operation without getting the ValueError.