Extract non-zero elements from matrix with double precision numbers

How can I extract all of the non-zero number from a matrix? I tried using the function nonzero(M), but since the values in the matrix are all decimals, I got the error "Undefined function 'nonzero' for input arguments of type 'double' ".

I just wand a row vector (or column vector, or whatever is easiest) of all non-zero elements. Obviously I can just loop through each element, but this is insanely inefficient.

Answer 1

[Azzi Abdelmalek]

out=M(M~=0)

[Azzi Abdelmalek]

nonzeros(M) 

also should work (nonzeros with s)

Answer 2

[Matt Kindig]

notZeros= M(M~=0);

Keep in mind that due to numerical precision, some of your matrix elements may be small but not identically zero. You might want to use some sort of tolerance instead, such as:

notZeros = M(abs(M)<10*eps);  %for example