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NumPy - amax() function



The NumPy amax() function returns the maximum of an array or maximum along the specified axis.

Syntax

numpy.amax(a, axis=None, out=None, keepdims=<no value>)

Parameters

a Required. Specify the input array.
axis Optional. Specify axis or axes along which to operate. The default, axis=None, operation is performed on flattened array.
out Optional. Specify the output array in which to place the result. It must have the same shape as the expected output.
keepdims Optional. If this is set to True, the reduced axes are left in the result as dimensions with size one. With this option, the result will broadcast correctly against the input array.

Return Value

Returns maximum of a. If axis is None, the result is a scalar value. If axis is given, the result is an array of dimension a.ndim - 1.

Example: amax() of flattened array

In the example below, amax() function is used to return the maximum of all values present in the array.

import numpy as np
Arr = np.array([[10,20],[30, 40]])

print("Array is:")
print(Arr)

#maximum of all values
print("\nMaximum of all values:", np.amax(Arr))

The output of the above code will be:

Array is:
[[10 20]
 [30 40]]

Maximum of all values: 40

Example: amax() with axis parameter

When axis parameter is provided, maximum is calculated over the specified axes as shown in the example below.

import numpy as np
Arr = np.array([[10,20,30],[70,80,90]])

print("Array is:")
print(Arr)

#maximum along axis=0
print("\nMaximum along axis=0")
print(np.amax(Arr, axis=0))

#maximum along axis=1
print("\nMaximum along axis=1")
print(np.amax(Arr, axis=1))

The output of the above code will be:

Array is:
[[10 20 30]
 [70 80 90]]

Maximum along axis=0
[70 80 90]

Maximum along axis=1
[30 90]

❮ NumPy - Functions

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