numpy.vstack() in python

numpy.vstack() is a function in NumPy used to stack arrays vertically (row-wise). It takes a sequence of arrays as input and returns a single array by stacking them along the vertical axis (axis 0).

Example: Vertical Stacking of 1D Arrays Using numpy.vstack()

1st Input array : 
 [1 2 3]
2nd Input array : 
 [4 5 6]
Output vertically stacked array:
 [[1 2 3]
 [4 5 6]]

The two 1D arrays a and b are stacked vertically using np.vstack(), combining them into a 2D array where each input array forms a row.

Syntax

numpy.vstack(tup)

Parameters:

• tup: [sequence of ndarrays] Tuple containing arrays to be stacked. The arrays must have the same shape along all but the first axis.

Return: [stacked ndarray] The stacked array of the input arrays.

Vertical Stacking of 2D Arrays Using numpy.vstack()

This code shows how to vertically stack two 2D arrays using numpy.vstack() resulting in a combined 2D array.

1st Input array : 
 [[ 1 2 3]
 [-1 -2 -3]]
2nd Input array : 
 [[ 4 5 6]
 [-4 -5 -6]]
Output stacked array :
 [[ 1 2 3]
 [-1 -2 -3]
 [ 4 5 6]
 [-4 -5 -6]]

Two 2D arrays a and b are vertically stacked, creating a new 2D array where each original array becomes a set of rows in the resulting array.