How to use numpy.vstack() in Python

How to use numpy.vstack() in Python

numpy.vstack() is a function in the NumPy library in Python that is used to stack arrays in a vertical direction.

The syntax for the numpy.vstack() function is as follows:

Syntax

numpy.vstack(tup)

Here, tup is a tuple containing the arrays to be stacked.

The function returns a single array that is the result of stacking the input arrays in the vertical direction.

Examples

Here are a few examples of how to use the numpy.vstack() function in Python:

import numpy as np

# Stack two 1-D arrays
array1 = np.array([1, 2, 3])
array2 = np.array([4, 5, 6])
stacked_array = np.vstack((array1, array2))
print(stacked_array)  # [[1 2 3]
                      #  [4 5 6]]

# Stack two 2-D arrays
array1 = np.array([[1, 2, 3], [4, 5, 6]])
array2 = np.array([[7, 8, 9], [10, 11, 12]])
stacked_array = np.vstack((array1, array2))
print(stacked_array)  # [[ 1  2  3]
                      #  [ 4  5  6]
                      #  [ 7  8  9]
                      #  [10 11 12]]

# Stack a 1-D and a 2-D array
array1 = np.array([1, 2, 3])
array2 = np.array([[4, 5, 6], [7, 8, 9]])
stacked_array = np.vstack((array1, array2))
print(stacked_array)  # [[1 2 3]
                      #  [4 5 6]
                      #  [7 8 9]]

In the first example, we stack two 1-D arrays to create a 2-D array.

In the second example, we stack two 2-D arrays to create a new 2-D array.

In the third example, we stack a 1-D array and a 2-D array to create a new 2-D array.

In all three examples, the numpy.vstack() function is used to stack the arrays in a vertical direction.