How to do this

Suppose I have a matrix with some entries zero and some are nonzero.

0.36   0     0.9   0.4

0.26   0.1   0     0

0.5    0     0     0.8

0.6    0.75  0.4   0.88

I have to take log of nonzero numbers and then I have to add it, i.e. log(0.36)+log(0.9)+log(0.4)+log(0.26)+log(0.1)+log(0.5)+log(0.8)+log(0.6)+log(0.75)+log(0.4)+log(0.88), how to do.

Answer 1

[Thorsten]

 A = [0.36   0     0.9   0.4
      0.26   0.1   0     0
      0.5    0     0     0.8
      0.6    0.75  0.4   0.88];

 sum(log(A(A ~= 0))