Performing math.sqrt on numpy structured array column

Question

I have a numpy structured array. The final column needs to contain the result of a simple math equation based on the other values in the row. Problem is I get the following error when trying to calculate the square root portion of the equation:

TypeError: only length-1 arrays can be converted to Python scalars

Limitation is that I cannot iterate the array to add the values one at a time.

Here's an example to show the error:

import numpy as np
import math

data = np.random.randint(-100, 100, (1, 6, 4))

data[:,3] = math.sqrt((0-data[:,0])**2 + (0-data[:,1])**2 + (0-data[:,2])**2)

Answer 1

您只需要使用np.sqrt而不是math.sqrt （后者仅适用于单个值）。