If your array arr has a length divisible by 3:
np.mean(arr.reshape(-1, 3), axis=1)
Reshaping to a higher dimensional array and then performing some form of reduce operation on one of the additional dimensions is a staple of numpy programming.
If your array arr has a length divisible by 3:
np.mean(arr.reshape(-1, 3), axis=1)
Reshaping to a higher dimensional array and then performing some form of reduce operation on one of the additional dimensions is a staple of numpy programming.