List of Matrix Exercises

Matrix Exercises 

Q1. Write a program to find the transpose of a 3x4 matrix e.g.

rows = int(input("Input number of rows: "))

cols = int(input("Input number of columns: "))

Matrix = [[0 for col in range(cols)] for row in range(rows)]

for row in range(rows):

    print("Enter values for row -> ",row)

    for col in range(cols):

        print("Matrix[",row,"][",col,"]-> ",end="")

        Matrix[row][col]=int(input()) # input elements from keyboard

print("\n Display Matrix ")

for row in range(rows):

    for col in range(cols):

        print(Matrix[row][col],end="\t")

    print()

print("\nTranspose of matrix")

for row in range(cols):

    for col in range(rows):

        print(Matrix[col][row],end="\t")

    print()

Q2. Write a program to find the sum of odd numbers in a matrix.

rows = int(input("Input number of rows: "))

cols = int(input("Input number of columns: "))

Matrix = [[0 for col in range(cols)] for row in range(rows)]

sum1=0

for row in range(rows):

    print("Enter values for row -> ",row)

    for col in range(cols):

        print("Matrix[",row,"][",col,"]-> ",end="")

        Matrix[row][col]=int(input()) # input elements from keyboard

        if(Matrix[row][col]%2!=0):

            sum1=sum1+Matrix[row][col]

print("\n Display Matrix ")

for row in range(rows):

    for col in range(cols):

        print(Matrix[row][col],end="\t")

    print()

print("Sum of odd number in a matrix ->", sum1)

Q3. Write a program to find the sum of rows and columns elements in a matrix.

Answer :

rows=int(input("Enter the number of rows -> "))

cols=int(input("Enter the number of columnbs -> "))

mat = [[0 for i in range(cols)] for j in range(rows)] 

for i in range(0, rows):  

    for j in range(0, cols):

        print("mat[",i,"][",j,"]= ", end=" ")

        mat[i][j]=int(input())

print("Display Matrix")

for i in range(0, rows):  

    for j in range(0, cols):

        print(mat[i][j],end="\t")

    print()

#Calculates sum of each row of given matrix  

for i in range(0, rows):  

    sumRow = 0 

    for j in range(0, cols):  

        sumRow = sumRow + mat[i][j]  

    print("Sum of " + str(i+1) +" row: " + str(sumRow))

   

#Calculates sum of each column of given matrix  

for i in range(0, rows):  

    sumCol = 0;  

    for j in range(0, cols):  

        sumCol = sumCol + mat[j][i]  

    print("Sum of " + str(i+1) +" column: " + str(sumCol))

Q4. Write a program to find the sum of diagonal principal and secondary elements in a matrix.

Answer: 

rows=int(input("Enter the number of rows -> "))

cols=int(input("Enter the number of columnbs -> "))

mat = [[0 for i in range(cols)] for j in range(rows)] 

principal = 0

secondary = 0;

for i in range(0, rows):  

    for j in range(0, cols):

        print("mat[",i,"][",j,"]= ", end=" ")

        mat[i][j]=int(input())

print("Display Matrix")

for i in range(0, rows):  

    for j in range(0, cols):

        print(mat[i][j],end="\t")

    print()

for i in range(0, rows):  

    for j in range(0, cols):  

        # Condition for principal diagonal 

        if (i == j): 

            principal += mat[i][j] 

        # Condition for secondary diagonal 

        if ((i + j) == (rows - 1)): 

            secondary += mat[i][j]    

print("Principal Diagonal:", principal)

print("Secondary Diagonal:", secondary)

OR

r=int(input("Enter the number of rows of matrix "))

c=int(input("Enter the number of columns of matrix "))

#Declration of matrix

A=[[0 for x in range(c)]for x in range(r)]

#Accept value from keyboard

for i in range(r): #for rows

    for j in range(c):#for columns

        print("A[%d][%d]=" %(i,j), end="")

        A[i][j]=int(input())

print("Display Matrix")

for i in range(r):

    for j in range(c):

        print(A[i][j], end="\t")#show cells values

    print()

print('Sum of diagonal values')

sum=0

for i in range(r):

    for j in range(c):

        if(i==j):

            sum=sum+A[i][j]

print("Principal Diagonal:", sum)

c=2

sum=0

for i in range(r):

    sum=sum+A[i][c]

    c=c-1

print("Secondary Diagonal:", sum)

Q5. Write python program to sum of two matrix/nested list.

rows=int(input("Enter the number of rows -> "))

cols=int(input("Enter the number of columnbs -> "))

mat = [[0 for i in range(cols)] for j in range(rows)]

mat1 = [[0 for i in range(cols)] for j in range(rows)]

matSum = [[0 for i in range(cols)] for j in range(rows)]

print("Input value First matrix ")

for i in range(0, rows): 

    for j in range(0, cols):

        print("mat[",i,"][",j,"]= ", end=" ")

        mat[i][j]=int(input())

print("Input value Second matrix ")

for i in range(0, rows): 

    for j in range(0, cols):

        print("mat1[",i,"][",j,"]= ", end=" ")

        mat1[i][j]=int(input())

print("*******Display Matrix1*******")

for i in range(0, rows): 

    for j in range(0, cols):

        print(mat[i][j],end="\t")

    print()

print("******Display Matrix2********")

for i in range(0, rows): 

    for j in range(0, cols):

        print(mat1[i][j],end="\t")

    print()

print("Sum of Two  matrix ")

for i in range(0, rows): 

    for j in range(0, cols):

        matSum[i][j]=mat[i][j]+mat1[i][j]

        print(matSum[i][j],end="\t")

    print()

Q6. Write a python program to calculate subtract of two matrix.

rows=int(input("Enter the number of rows -> "))

cols=int(input("Enter the number of columnbs -> "))

mat = [[0 for i in range(cols)] for j in range(rows)]

mat1 = [[0 for i in range(cols)] for j in range(rows)]

matSum = [[0 for i in range(cols)] for j in range(rows)]

print("Input value First matrix ")

for i in range(0, rows): 

    for j in range(0, cols):

        print("mat[",i,"][",j,"]= ", end=" ")

        mat[i][j]=int(input())

print("Input value Second matrix ")

for i in range(0, rows): 

    for j in range(0, cols):

        print("mat1[",i,"][",j,"]= ", end=" ")

        mat1[i][j]=int(input())

print("*******Display Matrix1*******")

for i in range(0, rows): 

    for j in range(0, cols):

        print(mat[i][j],end="\t")

    print()

print("******Display Matrix2********")

for i in range(0, rows): 

    for j in range(0, cols):

        print(mat1[i][j],end="\t")

    print()

print("Sum of Two  matrix ")

for i in range(0, rows): 

    for j in range(0, cols):

        matSum[i][j]=mat[i][j]-mat1[i][j]

        print(matSum[i][j],end="\t")

    print()

Q7. Write a python program to calculate multiplication of two matrix.

r=int(input("Enter the number of rows "))

c=int(input("Enter the number of columns "))

MatA=[[0 for x in range(c)]for x in range(r)]

MatB=[[0 for x in range(c)]for x in range(r)]

MatC=[[0 for x in range(c)]for x in range(r)]

#input value from keyboard

print("Input Matrix A")

for i in range(r):

    for j in range(c):

        print('MatA[%d][%d]='%(i,j),end="")

        MatA[i][j]=int(input())

print("Input Matrix B")

for i in range(r):

    for j in range(c):

        print('MatB[%d][%d]='%(i,j),end="")

        MatB[i][j]=int(input())

print("Matrix A")

for i in range(r):

    for j in range(c):

        print(MatA[i][j],end="\t")

    print()

print("Matrix B")

for i in range(r):

    for j in range(c):

        print(MatB[i][j],end="\t")

    print()

print("Multiplication of Two matrix")

for i in range(len(MatA)):  

   for j in range(len(MatB[0])):  

       for k in range(len(MatB)):  

           MatC[i][j] += MatA[i][k] * MatB[k][j]  

for r in MatC:  

   print(r)  

Q8. Write a program to input any matrix and print both diagonal values of the matrix.
Note : The matrix must be a square matrix, i.e. 3x3, 4x4, 5x5, etc.

Answer :

r=int(input("Enter the number of rows of matrix "))

c=int(input("Enter the number of columns of matrix "))

#Declration of matrix

A=[[0 for x in range(c)]for x in range(r)]

#Accept value from keyboard

for i in range(r): #for rows

    for j in range(c):#for columns

        print("A[%d][%d]=" %(i,j), end="")

        A[i][j]=int(input())

print("Display Matrix")

for i in range(r):

    for j in range(c):

        print(A[i][j], end="\t")#show cells values

    print()

print("Principal Diagonal :-> ", end="")

for i in range(r):

    for j in range(c):

        if(i==j):

            print(A[i][j],end="\t")

print('\nSecondary Diagonal:-> ',end="\t")

c=2

for i in range(r):

    print(A[i][c],end="\t")   

    c=c-1