Addtion of two matrix.

I am taking inputs from user to enter row n column and adding two matrix. But the output i am getting is of different dimension. please tell me what is the problem in given code.

m = input('Enter number of rows: '); 
n = input('Enter number of columns: '); 
for i = 1:m 
 for j = 1:n 
     str = ['Enter element in row ' num2str(i) ', col ' num2str(j) ': ']; 
     T(i,j) = input(str); 
 end 
end 
%a = input('Enter number of rows: '); 
%b = input('Enter number of columns: '); 
strn = ['Enter elements for matrix S']
for i = 1:m
  for j = 1:n
      strn = ['Enter element in row ' num2str(i) ', col ' num2str(j) ': ']; 
      S(i,j) = input(strn); 
  end 
end 
string= ['Addition is:']
for i=1:m
  for j=1:n
      C(i,j)=0;
  end
end
C(i,j)=0
for i= 1:m
  for j=1:n
     C(i,j)= T(i,j)+ S(i,j)
  end
end

[Vansh]

Thanks for sharing!

Answer 1

[dpb]

The problem is the line

C(i,j)=0

after the loop that creates the zero-filled array--when done, the i,j indices are one greater than the loop limit so this sets the element at C(m+1,n+1) to zero. Matlab automagically creates a full array of that size so the end result is always going to be one larger than the inputs in each direction.

Simply remove this line--it's not needed.

I presume you're doing this this way as a pedagogical exercise and realize all of these loops can be eliminated?

Also, I'd suggest adding the semicolon to the following line and then using

     C(i,j)= T(i,j)+ S(i,j)

disp(C)

at the end. Perhaps you were simply echoing output to command window for debugging, however.

Answer 2

[priyanka]

Thank you.

Answer 3

[Nalini Vishnoi]

Since MATLAB allows matrix manipulations directly, you can add 2 matrices A and B of the same size using a single line of code:

C = A + B;

and this should provide you with the desired result.

[MRUTUNJAY]

NICE STEP

[VINEET THAKUR]

Sometimes in learning we forced to not use build-in functions, so it's a good code.