Creating Empty, Zeroes, and Ones Arrays

Introduction

Arrays are a fundamental data structure in Numpy library. In this lab, we will learn how to create arrays in Numpy library using the empty, zeroes, and ones functions.

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Skills Graph

Creating an Empty Array using numpy.empty

numpy.empty is used to create an uninitialized array of specified shape and data type.

Syntax: numpy.empty(shape, dtype, order)

• shape: Desired shape of the array.
• dtype: Data type of the array element. Default is float.
• order: Order of the array. Default is c-style row-major. Set to 'F' for FORTRAN-style (column-major order).

Code:

import numpy as np

## Creating an array with 4 rows and 3 columns
x = np.empty([4,3], dtype = int)
print(x)

Output:

[[206 0 0]
 [0 0 0]
 [0 0 0]
 [0 0 0]]

Creating a Zero Value Array using numpy.zeros

numpy.zeros is used to create an array of specified shape with all elements initialized as 0.

Syntax: numpy.zeros(shape, dtype, order)

• shape: Desired shape of the array.
• dtype: Data type of the array element. Default is float.
• order: Order of the array. Default is c-style row-major. Set to 'F' for FORTRAN-style (column-major order).

Code:

import numpy as np

## Creating an array of dimension 3x3 with all elements initialized as 0
arr = np.zeros((3,3), dtype = int)
print(arr)

Output:

[[0 0 0]
 [0 0 0]
 [0 0 0]]

Creating a One Value Array using numpy.ones

numpy.ones is used to create an array of specified shape with all elements initialized as 1.

Syntax: numpy.ones(shape, dtype, order)

• shape: Desired shape of the array.
• dtype: Data type of the array element. Default is float.
• order: Order of the array. Default is c-style row-major. Set to 'F' for FORTRAN-style (column-major order).

Code:

import numpy as np

## Creating an array of dimension 3x3 with all elements initialized as 1
arr = np.ones((3,3), dtype = int)
print(arr)

Output:

[[1 1 1]
 [1 1 1]
 [1 1 1]]

Summary

In this lab, we learned how to create arrays using the empty, zeroes, and ones functions in Numpy library. We covered the syntax, parameters, and examples for each function.