Introduction To Numpy In Python

In this article, we will learn about Numpy. what is Numpy, uses of Numpy, application of Numpy, How to install Nupmy, and perform some examples for more understanding.

What is Numpy?

NumPy is the fundamental package for scientific computing in Python. It is a Python library that provides a multidimensional array object, various derived objects (such as masked arrays and matrices), and an assortment of routines for fast operations on arrays, including mathematical, logical, shape manipulation, sorting, selecting, I/O, discrete Fourier transforms, basic linear algebra, basic statistical operations, random simulation and much more.

Why use Numpy?

• NumPy arrays are faster and more compact than Python lists. An array consumes less memory and is convenient to use. NumPy uses much less memory to store data and it provides a mechanism of specifying the data types.
• NumPy aims to provide an array object that is up to 50x faster than traditional Python lists.
• Arrays are very frequently used in data science, where speed and resources are very important.

Applications of Numpy

There are a number of applications of Numpy applications as well as the areas where the Numpy library is used in python. Some of them are listed below:

1) Shape Manipulations

If the output produces the same number of elements then the user can change array dimensions at the runtime. np. reshape(…) function is applied on the array to reshape it.

2) Array Generation

We generate the array data set for implementing various functions. We can also generate a predefined set of numbers for the array elements using the np.arrange(…)function. Reshape function is useful to generate a different set of dimensions.

3) NumPy with SciPy

Scipy is an open-source library in Python. It is the most important scientific library in python. It has been built upon the functionalities of NumPy.There are advanced functionalities in SciPy for scientific computations.

4) NumPy with Tkinter

Tkinter is a standard library for GUI. We use Tkinter for the GUI representation of the NumPy data. Its combination with NumPy can implement fast and easy GUIs.

Installation Process

Before we move on with the code for understanding the NumPy Arrays, let’s get Numpy installed in your system using the following command.

pip install numpy

Numpy Array Uses:

1) Creating array using NumPy

NumPy is used to work with arrays. The array object in NumPy is called ndarray.

import numpy as np

arr = np.array([1, 2, 3, 4, 5])
print(arr)
print(type(arr))

2) NumPy Array Indexing

Array indexing is the same as accessing an array element. You can access an array element by referring to its index number.

import numpy as np 

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

3) Array of zeros

NumPy lets you create an array of all zeros using the np.zeros() method. All you have to do is pass the shape of the desired array:

import numpy as np 

np.zeros(5) //1-D array
#output 
array([0., 0., 0., 0., 0.]) 

np.zeros((2,3)) //2-D array
#output 
array([[0., 0., 0.], [0., 0., 0.]])

4) Array of ones

np.ones(5,dtype=np.int32)
#output
array([1, 1, 1, 1, 1])

import numpy as np

arr = np.array([3,6,9,12])
np.reshape(arr,(2,2))

#output
array([[ 3,  6],
       [ 9, 12]])