MATLAB: Sum of the element occurence

Question

Greetings Matlab Community,

I've manage to sum up the occurrence of number 2 of the entire matrix by using this,

chromo = [1 1 2 4 6 1 ; 2 1 3 5 7 2];
sum(chromo(:) == 2)

How do i sum up the occurrence of number 2 in just a row in the matrix and not the entire matrix?

Answer 1

If A is the matrix, you can do this as follow

numOfTwos = sum(A==2, 2);
myResult = numOfTwos(rowNumber);

The above will numOfTwos will give number fo two in all the rows of matrix A. If you just want it for one row, use

numOfTwos = sum(A(rowNumber, :) ==2, 2);