NumPy: Stack 1-D arrays as columns wise

Last update on August 29 2025 12:45:54 (UTC/GMT +8 hours)

Stack 1D Arrays as Columns

Write a NumPy program to stack 1-D arrays columns wise.

Sample Solution:

Python Code:

# Importing the NumPy library and aliasing it as 'np'
import numpy as np

# Printing a message indicating the original arrays will be displayed
print("\nOriginal arrays:")

# Creating a NumPy array 'x' with elements 1, 2, and 3
x = np.array((1, 2, 3))

# Creating another NumPy array 'y' with elements 2, 3, and 4
y = np.array((2, 3, 4))

# Printing a message for Array-1 and displaying the contents of array 'x'
print("Array-1")
print(x)

# Printing a message for Array-2 and displaying the contents of array 'y'
print("Array-2")
print(y)

# Stacking Array-1 'x' and Array-2 'y' as columns using np.column_stack()
new_array = np.column_stack((x, y))

# Printing a message indicating the stacking of 1-D arrays as columns and displaying the resulting new array
print("\nStack 1-D arrays as columns wise:")
print(new_array)

Sample Output:

Original arrays:
Array-1
[1 2 3]
Array-2
[2 3 4]

Stack 1-D arrays as columns wise:
[[1 2]
 [2 3]
 [3 4]]

Explanation:

In the above code –

x = np.array((1,2,3)): This line creates a 1-dimensional NumPy array ‘x’ with the elements 1, 2, and 3.

y = np.array((2,3,4)): This line creates another 1-dimensional NumPy array ‘y’ with the elements 2, 3, and 4.

new_array = np.column_stack((x, y)): It stacks the two 1-dimensional arrays x and y column-wise to form a new 2-dimensional array new_array.

Finally print() function prints the new_array.

Pictorial Presentation:

Python NumPy: Stack 1-D arrays as columns wise.

For more Practice: Solve these Related Problems:

Write a NumPy program to stack two 1D arrays as columns using np.column_stack and verify the 2D output.
Create a function that transforms multiple 1D arrays into a single 2D column-stacked array.
Test the column stacking with arrays of varying lengths and ensure proper error handling.
Implement a solution using np.newaxis to convert 1D arrays to column vectors before stacking.

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