Get the index of the max value in an array in NumPy

Getting the position of the max value in a NumPy array:

import numpy as np

a = np.array([5, 6, 7, 4])
b = np.array([3, 2, 1])

i = np.argmax(a)
j = np.argmax(b)

print(i)  # 2
print(j)  # 0

argmax() returns the index of the max value. In fact, a[2] and b[0] are max values respectively in a and b. If the array has maximum values at multiple positions, argmax() returns the first index of that.

import numpy as np

a = np.array([5, 6, 7, 7, 4])

i = np.argmax(a)

print(i)  # 2

max()

NumPy has the max() that is confusing with argmax() but both are totally different.

import numpy as np

a = np.array([5, 6, 7, 7, 4])

i = np.max(a)

print(i)  # 7

The max() returns the maximum value of an NumPy array.

NumPy Array

NumPy Tutorial