Python program to print an identity matrix :

In this tutorial,we will learn how to print a identity matrix in python. A matrix is called *identity matrix* if all of its digonal elements from upper left corner to bottom right corner is *1* and all other elements are *0*. For example, following matrix are identity matrix :

1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 1 0 0 1 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1

In our program, we will ask the user to enter the size of the matrix and then we will print the identity matrix . Let’s take a look at the program :

### Python program to print an identity matrix :

#1 size = int(input("Enter the size of the matrix : ")) #2 for i in range(0,size): #3 for j in range(0,size): #4 if(i==j): print("1",end = " ") else: print("0",end = " ") #5 print()

### Explanation :

The main idea behind printing a identity matrix is that the its value will be equal to *1* if current row number is equal to the current column number. For first row, *matrix[0][0]* is *1*, for the second row, *matrix[1][1]* is *1* etc. So, to print the matrix, we will use two *for loops* and if both the counters of both for loops is same, print *1* . Else, print *0*.

*The commented numbers in the above program denote the step number below :*

1. Ask the user to enter the size of the matrix and save it in variable *size*.

2. Run one *for loop* from *0* to *size of the matrix – 1*.

3. Start one more *inner for loop* and run it from *0* to *size of the matrix – 1*.

4. Check if *i* is equal to *j* or not. If yes, print *1* , else print *0*.

5. Print one new line.

### Sample Output :

Enter the size of the matrix : 5 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 Enter the size of the matrix : 10 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 Enter the size of the matrix : 2 1 0 0 1