Error using vertcat Dimensions of arrays being concatenated are not consistent.

   matrix1 = input("matrix 1 is \n");
   matrix2 = input("matrix 2 is \n");
   
   [M, N] = size(matrix1);
   [P, Q] = size(matrix2');

   if N == P
      X = matrix1*matrix2
      disp(X)
   else
      fprintf("Matrix multiplication can't be done.")
   end

This is my code and we are tasked to do simple multiplication of matrices. This works fine in 2x2 or 1x1 or even 16x16 matrices but when it comes to 1x3 or 3x4 or 5x7, it doesnt work anymore. Thank you for answering

[KSSV]

What is c, d, I, J? Variables are not defined, how do you expect us to help you?

[Jerico Yabut]

Thanks for pointing that out. I already edited it.

Answer 1

[David Hill]

   matrix1 = input("matrix 1 is \n");
   matrix2 = input("matrix 2 is \n");
   
   [M, N] = size(matrix1);
   [P, Q] = size(matrix2);
   if N == P
      X = matrix1*matrix2;
      disp(X)
   else
      fprintf("Matrix multiplication can't be done.")
   end

[Jerico Yabut]

I tried this however it doesn't work at 1x3 or 4x1 or 5x7. It only works on let's just say 4x4 or 2x2 or 10x10.it says that "Error using vertcat Dimensions of arrays being concatenated are not consistent."

Answer 2

[VBBV]

   matrix1 = rand(1,3)%input("matrix 1 is \n");  This is example of 1 x3 matrix 

matrix1 = 1×3

0.7567 0.2314 0.3456

   matrix2 = rand(3,3)%input("matrix 2 is \n");

matrix2 = 3×3

0.2531 0.3500 0.0379 0.0466 0.7056 0.3046 0.0829 0.0319 0.9818

   
   [M, N] = size(matrix1);
   [P, Q] = size(matrix2);

   if N == P
      disp('The product is ') 
      X = matrix1.*matrix2
   
   else
      fprintf("Matrix multiplication can't be done.")
   end

The product is 

X = 3×3

0.1915 0.0810 0.0131 0.0353 0.1633 0.1053 0.0627 0.0074 0.3393