How to Create a Vector or Matrix in Python?

In this article, we will show you how to create a vector or matrix in Python.

NumPy is a Python library designed to work efficiently with arrays in Python. It is fast, simple to learn, and efficient in storage. In NumPy, we may generate an n-dimensional array.

What are vectors?

In python, vectors are built from components, which are ordinary numbers. A vector can be considered as a list of numbers, and vector algebra as operations done on the numbers in the list. In other words, a vector is the numpy 1-D array.

We use the np.array() method to create a vector.

Syntax

np.array(list) 

Parameters

• list ? a 1-D list, which can have one row and n columns or n rows and one column.

Return value ? returns vector(numpy.ndarray)

Creating a Horizontal Vector from a given list

In this method, we create a horizontal vector from the list using the numpy.array() function.

Algorithm (Steps)

Following are the Algorithm/steps to be followed to perform the desired task ?

• Use the import keyword to import the NumPy module with an alias name.

• Create a variable to store a Horizontal 1-Dimensional list.

• Use the numpy.array() function(returns an ndarray. The ndarray is an array object that satisfies the given requirements) to create a vector_1 by passing given list_1 as an argument to it i.e, vector as a row.

• Print the resultant horizontal vector.

The following program creates the horizontal vector from the list using the NumPy array() function and returns it ?

Example

 # importing numpy module with an alias name import numpy as np # creating a Horizontal 1-Dimensional list  list_1 = [ 15, 20, 25, 'Hello', 'TutorialsPoint'] # creating a vector(numpy array) of the horizontal list  # This is the horizontal vector vector_1 = np.array(list_1) print('Given List =',list_1) # printing the resultant horizontal vector print("The resultant horizontal vector:") print(vector_1) 
 
 
 

Output

On executing, the above program will generate the following output ?

Given List = [15, 20, 25, 'Hello', 'TutorialsPoint'] The resultant horizontal vector: ['15' '20' '25' 'Hello' 'TutorialsPoint'] 

Creating a Vertical Vector

In this method, we create a vertical vector using the numpy.array() function.

Algorithm (Steps)

Following are the Algorithm/steps to be followed to perform the desired task ?

• Use the import keyword to import the NumPy module with an alias name.

• Pass the vertical list as an argument to the numpy.array() function(returns an ndarray. The ndarray is an array object that satisfies the given requirements) and store this vertical vector in a variable.

• Print the resultant vertical vector.

Example

The following program creates the vertical vector using the NumPy array() function and returns it ?

 # importing NumPy module with an alias name import numpy as np # Passing vertical list as an argument to array() function  # creating a vertical vector(NumPy array) of the second list  vector_2 = np.array([[5], [40], [20], ['Hello'], ['TutorialsPoint']]) # printing the resultant vertical vector print("The resultant vertical vector:") print(vector_2) 
 
 
 

Output

On executing, the above program will generate the following output ?

The resultant vertical vector: [['5'] ['40'] ['20'] ['Hello'] ['TutorialsPoint']] 

Creating a Matrix using numpy.mat() function

In this method, we create a matrix using the numpy.mat() function.

In Python, the mat() method is used to convert an array into a matrix.

Parameters

The mat() function accepts the following arguments ?

• data ? This is the input data or an array like object.

• dtype ? This represents the output matrix's data type.

Return Value

The mat() method interprets the input as a matrix and returns it.

Algorithm (Steps)

Following are the Algorithm/steps to be followed to perform the desired task ?

• Use the import keyword to import the NumPy module with an alias name.

• Pass the nested list(list of lists) as an argument to the numpy.mat() function(the mat() method is used to convert an array into a matrix) and store this matrix in a variable.

• Print the resultant matrix.

Example

The following program creates the matrix using the Numpy mat() function and returns it ?

 # importing numpy module with an alias name import numpy as np # Creating a matrix using numpy.mat() function inputMatrix = np.mat([[1, 2, 3], [4, 5, 6], [7, 8, 9]]) print("The created matrix is:") print(inputMatrix) 
 
 
 

Output

On executing, the above program will generate the following output ?

The created matrix is: [[1 2 3] [4 5 6] [7 8 9]] 

Creating a Matrix using numpy.matrix() function

In this method, we create a matrix using the numpy.matrix() function.

Parameters

The numpy.matrix() function accepts the following arguments ?

• data ? This is the input data or an array like object.

• dtype ? This represents the output matrix's data type.

Return Value:

A matrix representation of the data

Algorithm (Steps)

Following are the Algorithm/steps to be followed to perform the desired task ?

• Use the import keyword to import the NumPy module with an alias name.

• Pass the nested list(list of lists) as an argument to the numpy.matrix() function(From a string of data or an array-like object, this class returns a matrix. The resulting matrix is a specialized 2D array) and store this matrix in a variable.

• Print the resultant matrix.

Example

The following program creates the matrix using the Numpy matrix() function and returns it ?

 # importing numpy module with an alias name import numpy as np # Creating a matrix using numpy.matrix() function inputMatrix = np.matrix([[5, 3, 9, 11], [4, 5, 6, 23], [7, 8, 9, 84]]) print("The created matrix is:") print(inputMatrix) 
 
 
 

Output

On executing, the above program will generate the following output ?

The created matrix is: [[ 5 3 9 11] [ 4 5 6 23] [ 7 8 9 84]] 

Conclusion

In this tutorial, we learned two distinct ways to generate matrices in Python, as well as how to create vertical and horizontal vectors.