Sum of certain value in a matrix

I have a 241 x 340 matrix that contains only 1 and 0 value scattered over the matrix. My question is how can I calculate the sum value of 1 in the matrix? Thank You in advance. for example

A = [0 0 0 0 1 1 1 1 0 0 1 1 1 0; 1 1 1 0 0 1 1 1 0 0 0 1 1 0]

Answer 1

[Andrei Bobrov]

out = sum(A(:))

[EMIRA SYAMIMI AHMAD SUBRI]

Thank you so much! worked like a charm

[EMIRA SYAMIMI AHMAD SUBRI]

and one more, if I want the average of it, so i just change 'sum' to 'mean' is it?

[Andrei Bobrov]

yes

Answer 2

[KL]

See Image Analyst's answer here

A = [0 0 0 0 1 1 1 1 0 0 1 1 1 0; 1 1 1 0 0 1 1 1 0 0 0 1 1 0]
edges = unique(A)
counts = histc(A(:), edges)

Answer 3

[Aniruddha Katre]

See the documentation for nnz: http://www.mathworks.com/help/matlab/ref/nnz.html