Python Program for Frequencies of Even and Odd Numbers in a Matrix

In the previous article, we have discussed Python Program to Check Diagonally Dominant Matrix

Given a square matrix, the task is to get the frequency of even numbers and odd numbers of a given matrix in python.

What is a matrix:

A matrix is a rectangular sequence of numbers divided into columns and rows. A matrix element or entry is a number that appears in a matrix.

Example:

Above is the matrix which contains 5 rows and 4 columns and having elements from 1 to 20.

In this order, the dimensions of a matrix indicate the number of rows and columns.

Here as there are 5 rows and 4 columns it is called a 5*4 matrix.

Examples:

Example1:

Input:

Given Matrix :
9 0 2
7 5 6
7 1 9

Output:

The odd number frequency of the given matrix = 6
The even number frequency of the given matrix  3

Example2:

Input:

Given Matrix :
5 3 2
8 4 1
7 2 3

Output:

 The odd number frequency of the given matrix = 5
The even number frequency of the given matrix 4

Program for Frequencies of Even and Odd Numbers in a Matrix

Below are the ways to get the frequency of even numbers and odd numbers of a given matrix in python:

Using For Loop (Static Input)
Using For loop (User Input)

Method #1: Using For Loop (Static Input)

Approach:

Give the matrix as static input and store it in a variable.
Calculate the number of rows of the given matrix by calculating the length of the nested list using the len() function and store it in a variable mtrxrows.
Calculate the number of columns of the given matrix by calculating the length of the first list in the nested list using the len() function and store it in a variable mtrxcolums.
Take a variable to say evnnum_freqcy and initialize its value to 0.
Take another variable to say oddnum_freqcy and initialize its value to 0.
Loop till the given number of rows using the For loop.
Inside the For loop, Iterate till the given number of columns using another Nested For loop(Inner For loop).
Check if the mtrx[n][m] is even using the if conditional statement (where n is the iterator value of the parent For loop and m is the iterator value of the inner For loop.).
If it is true, then increment the value of above evnnum_freqcy by 1.
Else increment the value of above oddnum_freqcy by 1.
Print the frequency of even numbers and odd numbers of a given matrix.
The Exit of the Program.

Below is the implementation:

# Give the matrix as static input and store it in a variable.
mtrx = [[9, 0, 2],
        [7, 5, 6],
        [7, 1, 9]]
# Calculate the number of rows of the given matrix by
# calculating the length of the nested list using the len() function
# and store it in a variable mtrxrows.
mtrxrows = len(mtrx)
# Calculate the number of columns of the given matrix by
# calculating the length of the first list in the nested list
# using the len() function and store it in a variable mtrxcols.
mtrxcols = len(mtrx[0])
# Take a variable to say evnnum_freqcy and initialize its value to 0.
evnnum_freqcy = 0
# Take another variable to say oddnum_freqcy and initialize its value to 0.
oddnum_freqcy = 0
# Loop till the given number of rows using the For loop.
for n in range(mtrxrows):
  # Inside the For loop, Iterate till the given number of columns using another Nested
  # For loop(Inner For loop).
    for m in range(mtrxcols):
        # Check if the mtrx[n][m] is even using the if conditional statement (where n is the
        # iterator value of the parent For loop and m is the iterator value of the
        # inner For loop.).

        if ((mtrx[n][m] % 2) == 0):
         # If it is true, then increment the value of above evnnum_freqcy by 1.
            evnnum_freqcy += 1
        else:
           # Else increment the value of above oddnum_freqcy by 1.
            oddnum_freqcy += 1
# Print the frequency of even numbers and odd numbers of a given matrix.
print(" The odd number frequency of the given matrix =", oddnum_freqcy)
print(" The even number frequency of the given matrix ", evnnum_freqcy)

Output:

The odd number frequency of the given matrix = 6
 The even number frequency of the given matrix  3

Method #2: Using For loop (User Input)

Approach:

Give the number of rows of the matrix as user input using the int(input()) function and store it in a variable.
Give the number of columns of the matrix as user input using the int(input()) function and store it in another variable.
Take a list and initialize it with an empty value using [] or list() to say gvnmatrix.
Loop till the given number of rows using the For loop
Inside the For loop, Give all the row elements of the given Matrix as a list using the list(),map(),int(),split() functions and store it in a variable.
Add the above row elements list to gvnmatrix using the append() function.
Take a variable to say evnnum_freqcy and initialize its value to 0.
Take another variable to say oddnum_freqcy and initialize its value to 0.
Loop till the given number of rows using the For loop.
Inside the For loop, Iterate till the given number of columns using another Nested For loop(Inner For loop).
Check if the mtrx[n][m] is even using the if conditional statement (where n is the iterator value of the parent For loop and m is the iterator value of the inner For loop.).
If it is true, then increment the value of above evnnum_freqcy by 1.
Else increment the value of above oddnum_freqcy by 1.
Print the frequency of even numbers and odd numbers of a given matrix.
The Exit of the Program.

Below is the implementation:

# Give the number of rows of the matrix as user input using the int(input()) function
# and store it in a variable.
mtrxrows = int(input('Enter some random number of rows of the matrix = '))
# Give the number of columns of the matrix as user input using the int(input()) function
# and store it in another variable.
mtrxcols = int(input('Enter some random number of columns of the matrix = '))
# Take a list and initialize it with an empty value using [] or list() to say gvnmatrix.
mtrx = []
# Loop till the given number of rows using the For loop
for n in range(mtrxrows):
    # Inside the For loop, Give all the row elements of the given Matrix as a list using
    # the list(),map(),int(),split() functions and store it in a variable.
    l = list(map(int, input(
        'Enter {'+str(mtrxcols)+'} elements of row {'+str(n+1)+'} separated by spaces = ').split()))
    # Add the above row elements list to gvnmatrix using the append() function.

    mtrx.append(l)

# Take a variable to say evnnum_freqcy and initialize its value to 0.
evnnum_freqcy = 0
# Take another variable to say oddnum_freqcy and initialize its value to 0.
oddnum_freqcy = 0
# Loop till the given number of rows using the For loop.
for n in range(mtrxrows):
  # Inside the For loop, Iterate till the given number of columns using another Nested
  # For loop(Inner For loop).
    for m in range(mtrxcols):
        # Check if the mtrx[n][m] is even using the if conditional statement (where n is the
        # iterator value of the parent For loop and m is the iterator value of the
        # inner For loop.).

        if ((mtrx[n][m] % 2) == 0):
         # If it is true, then increment the value of above evnnum_freqcy by 1.
            evnnum_freqcy += 1
        else:
           # Else increment the value of above oddnum_freqcy by 1.
            oddnum_freqcy += 1
# Print the frequency of even numbers and odd numbers of a given matrix.
print(" The odd number frequency of the given matrix =", oddnum_freqcy)
print(" The even number frequency of the given matrix ", evnnum_freqcy)

Output:

Enter some random number of rows of the matrix = 3
Enter some random number of columns of the matrix = 3
Enter {3} elements of row {1} separated by spaces = 5 3 2
Enter {3} elements of row {2} separated by spaces = 8 4 1
Enter {3} elements of row {3} separated by spaces = 7 2 3
The odd number frequency of the given matrix = 5
The even number frequency of the given matrix 4

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