# To find the Maximum and Minimum value in a NumPy Array

In this tutorial, we’ll learn about NumPy library, NumPy array and how to calculate the maximum and minimum value in NumPy array.

`np.amax(array)`
`np.amin(array)`

These two functions can be used to achieve our target here.

## The maximum and minimum value in NumPy Array

```import numpy as np

# 1D array
arr = np.arange(10)
print("arr : ", arr)
print("Maximum of arr : ", np.amax(arr))
print("Minimum of arr : ", np.amin(arr))

# 2D array
arr = np.arange(10).reshape(2, 5)
print("\narr : ", arr)

# Maximum and minimum of the flattened array
print("\nMax of arr, axis = None : ", np.amax(arr))
print("\nMin of arr, axis = None : ", np.amin(arr))

# Maxima and minima along the first axis
# axis 0 means vertical
print("Max of arr, axis = 0 : ", np.amax(arr, axis = 0))
print("Min of arr, axis = 0 : ", np.amin(arr, axis = 0))

# Maxima and minima along the second axis
# axis 1 means horizontal
print("Max of arr, axis = 1 : ", np.amax(arr, axis = 1))
print("Min of arr, axis = 1 : ", np.amin(arr, axis = 1))```

Output:

```arr :  [0 1 2 3 4 5 6 7 8 9]
Max of arr :  9
Min of arr :  0

arr :  [[0 1 2 3 4]
[5 6 7 8 9]]

Max of arr, axis = None :  9

Min of arr, axis = None :  0
Max of arr, axis = 0 :  [5 6 7 8 9]
Min of arr, axis = 0 :  [0 1 2 3 4]
Max of arr, axis = 1 :  [4 9]
Min of arr, axis = 1 :  [0 5]

```

In the code above we have used 2 new functions:

• Numpy.amax()

It is used to calculate the value of the maximum in an array. However, if the axis is mentioned it will find the maximum value along the mentioned axis.

Syntax of NumPy.amax() :

`numpy.amax(arr, axis = None, out = None, keepdims = <class numpy._globals._NoValue>)`
• Numpy.amin()

It is used to calculate the value of the minimum in an array. Although if the axis is mentioned it will find the minimum value along the mentioned axis.

Syntax of NumPy.amin() :

`numpy.amin(arr, axis = None, out = None, keepdims = <class numpy._globals._NoValue>)`

Parameters:

1. Arr: It is the input data in the form of an array.
2. Axis: It specifies the axis along which we want to calculate the maximum value.
3. Out: It is an array in which the result will be stored. It is optional.
4. Keepdims: If set to true, the axes which are reduced will be left in the result as dimensions size 1.