# Introduction to NumPy for numerical computing

NumPy is a powerful and versatile library for Python developers, providing a range of features for data manipulation and analysis. In this article, we’ll explore the fundamentals of NumPy, including what it is, its history, key features, and benefits. We’ll also take a look at how to get started with NumPy, including installation, basic syntax, and creating arrays. Finally, we’ll discuss how to use NumPy for numerical computing, including mathematics, linear algebra, and statistics.

## What is NumPy?

NumPy is an open source scientific computing library used for numerical computing in Python. It is the foundation for a number of other packages used in data science and machine learning, such as SciPy and scikit-learn. NumPy is used for efficient manipulation of large multidimensional arrays and matrices, and for providing a large collection of mathematical functions.

### A. Definition

NumPy is a library for the Python programming language, providing support for large, multi-dimensional arrays and matrices, along with a large collection of mathematical functions to operate on these arrays. It is the fundamental package for scientific computing with Python. NumPy gives developers a high-performance multidimensional array object, and tools for working with these arrays.

### B. History

NumPy was created in 2005 by Travis Oliphant. It was first released as an open source project in 2006. It was designed to integrate with the Python programming language and to replace the earlier Numeric and Numarray libraries. The name “NumPy” is derived from the phrase “Numeric Python”.

### C. Key Features

NumPy is packed with features that make it a powerful tool for numerical computing. Here are some of the key features of NumPy:

• Powerful N-dimensional array object
• Tools for integrating C/C++ and Fortran code
• Useful linear algebra, Fourier transform, and random number capabilities
• Tools for integrating with other libraries like SciPy and Matplotlib

## Benefits of Using NumPy

NumPy offers a wide range of benefits for data manipulation and analysis. Here are some of the key benefits:

• Speed & Efficiency – NumPy is much faster than traditional lists in Python when it comes to working with large datasets. NumPy uses pre-allocated memory, which makes it faster and more efficient than other Python libraries.
• Easy array manipulation – NumPy makes it easy to manipulate arrays and matrices, allowing developers to easily perform calculations and transformations on the data.
• Broadcasting Functionality – NumPy provides powerful broadcasting capabilities that enable developers to easily manipulate arrays of different shapes.

## Getting Started with NumPy

If you’re new to NumPy, here’s how to get started.

### A. Installation NumPy can be easily installed using the Python Package Index (PyPI). To install NumPy, simply run the following command:

pip install numpy


Once you’ve installed NumPy, you can import it into your Python script by using the “import” statement:

import numpy as np


### B. Basic Syntax NumPy uses a special array object called a ndarray. It is short for n-dimensional array. The ndarray object is a multi-dimensional array used for efficient storage and manipulation of data. The most basic syntax for creating an ndarray is as follows:

array = np.array( [1,2,3,4] )


This creates a one-dimensional array with four elements. You can also create a two-dimensional array using the following syntax:

array = np.array( [[1,2,3,4], [5,6,7,8]] )


This creates a two-dimensional array with two rows and four columns.

### C. Creating Arrays NumPy provides a range of functions for creating arrays. Here are a few of the most commonly used functions:

• np.arange() – creates an array of evenly spaced values over a specified interval
• np.zeros() – creates an array of zeros
• np.ones() – creates an array of ones
• np.random.rand() – creates an array of random numbers

## Using NumPy for Mathematical Functions NumPy is also commonly used for mathematical functions. Here are a few of the most commonly used mathematical functions in NumPy:

### A. Mathematical Operations NumPy provides an extensive range of mathematical operations, including addition, subtraction, multiplication, division, and more. For example, here’s how to add two NumPy arrays together:

a = np.array([1,2,3,4])
b = np.array([5,6,7,8])

c = a + b

print(c)
# [ 6  8 10 12]


### B. Linear Algebra NumPy also provides a range of linear algebra functions, such as matrix multiplication, matrix decomposition, and more. For example, here’s how to calculate the inverse of a matrix using NumPy:

a = np.array([[1,2],
[3,4]])

a_inv = np.linalg.inv(a)

print(a_inv)
# [[-2.   1. ]
#  [ 1.5 -0.5]]


### C. Statistics NumPy also provides a range of statistical functions, such as mean, median, standard deviation, and more. For example, here’s how to calculate the mean of a NumPy array:

a = np.array([1,2,3,4])

mean = np.mean(a)

print(mean)
# 2.5