How to calculate the mean value of the non vero value in a vector?

How to calculate the mean value of the non vero value in a vector?

For example there is a vector contains 3 values M = [0.7,0.3,0]

the mean value in this case should be 0.5

Answer 1

[Star Strider]

M = [0.7,0.3,0];
Mmean = mean(M(M~=0))

Mmean = 0.5000

Answer 2

[James Tursa]

Another way that doesn't require any data copying:

M = [0.7,0.3,0];
sum(M)/nnz(M)

ans = 0.5000

Be aware that if there are no non-zero elements, this will return NaN (same as Star's method).