The numpy.argmax() function returns indices of the max element of the array in a particular axis.
Syntax :
numpy.argmax(array, axis = None, out = None)
Parameters :
array : Input array to work on
axis : [int, optional]Along a specified axis like 0 or 1
out : [array optional]Provides a feature to insert output to the out
array and it should be of appropriate shape and dtype
Return :
Array of indices into the array with same shape as array.shape with the dimension along axis removed.
Code 1 :
Python
# Python Program illustrating# working of argmax()import numpy as geek# Working on 2D arrayarray = geek.arange(12).reshape(3, 4)print("INPUT ARRAY : \n", array)# No axis mentioned, so works on entire arrayprint("\nMax element : ", geek.argmax(array))# returning Indices of the max element# as per the indicesprint("\nIndices of Max element : ", geek.argmax(array, axis=0))print("\nIndices of Max element : ", geek.argmax(array, axis=1)) |
Output :
INPUT ARRAY : [[ 0 1 2 3] [ 4 5 6 7] [ 8 9 10 11]] Max element : 11 Indices of Max element : [2 2 2 2] Indices of Max element : [3 3 3]
Code 2 :
Python
# Python Program illustrating# working of argmax()import numpy as geek# Working on 2D arrayarray = geek.random.randint(16, size=(4, 4))print("INPUT ARRAY : \n", array)# No axis mentioned, so works on entire arrayprint("\nMax element : ", geek.argmax(array))# returning Indices of the max element# as per the indices''' [[ 0 3 8 13] [12 11 2 11] [ 5 13 8 3] [12 15 3 4]] ^ ^ ^ ^ 12 15 8 13 - element 1 3 0 0 - indices'''print("\nIndices of Max element : ", geek.argmax(array, axis = 0))''' ELEMENT INDEX ->[[ 0 3 8 13] 13 3 ->[12 11 2 11] 12 0 ->[ 5 13 8 3] 13 1 ->[12 15 3 4]] 15 1 '''print("\nIndices of Max element : ", geek.argmax(array, axis = 1)) |
Output :
INPUT ARRAY : [[ 0 3 8 13] [12 11 2 11] [ 5 13 8 3] [12 15 3 4]] Max element : 15 Indices of Max element : [1 3 0 0] Indices of Max element : [3 0 1 1]
Code 3 :
Python
# Python Program illustrating# working of argmax()import numpy as geek# Working on 2D arrayarray = geek.arange(10).reshape(2, 5)print("array : \n", array)array[0][1] = 6print("\narray : \n", array) # Returns max elementprint("\narray : ", geek.argmax(array))# First occurrence of an max element is givenprint("\nMAX ELEMENT INDICES : ", geek.argmax(array, axis = 0)) |
Output :
array : [[0 1 2 3 4] [5 6 7 8 9]] array : [[0 6 2 3 4] [5 6 7 8 9]] array : 9 MAX ELEMENT INDICES : [1 0 1 1 1]
References :
https://docs.scipy.org/doc/numpy-dev/reference/generated/numpy.argmax.html#numpy.argmax
Note :
These codes won’t run on online IDE’s. Please run them on your systems to explore the working.
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