numpy.vstack() in python

numpy.vstack() function is used to stack the sequence of input arrays vertically to make a single array.

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.

Code #1 :

# Python program explaining
# vstack() function

import numpy as geek

# input array
in_arr1 = geek.array([ 1, 2, 3] )
print ("1st Input array : \n", in_arr1)

in_arr2 = geek.array([ 4, 5, 6] )
print ("2nd Input array : \n", in_arr2)

# Stacking the two arrays vertically
out_arr = geek.vstack((in_arr1, in_arr2))
print ("Output vertically stacked array:\n ", out_arr)

Output:

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

Code #2 :

# Python program explaining
# vstack() function

import numpy as geek

# input array
in_arr1 = geek.array([[ 1, 2, 3], [ -1, -2, -3]] )
print ("1st Input array : \n", in_arr1)

in_arr2 = geek.array([[ 4, 5, 6], [ -4, -5, -6]] )
print ("2nd Input array : \n", in_arr2)

# Stacking the two arrays vertically
out_arr = geek.vstack((in_arr1, in_arr2))
print ("Output stacked array :\n ", out_arr)

Output:

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]]