How can I ignore 0 values when computing the mean over the third dimensional of a 3D matrix?

Hi,

I have a 3D matrix size 951x301x720 let call it A.

I want to get a 951x301 matrix B with the mean of A over the third dimension.

I computed the mean over the third dimension with B = mean(A,3) but I have a lot of zeros in my matrix and I do not want the mean to be affected by the 0 values.

How can I ignore the 0?

Thank you

Answer 1

[Asad (Mehrzad) Khoddam]

You can set 0 values to NaN. Then find the mean of non NaN values;

Ap=A;
Ap(Ap==0)=NaN;
B=mean(Ap,3,'omitnan')

[Rik]

Or, for old releases:

B=sum(A,3)./sum(A==0,3);

[Asad (Mehrzad) Khoddam]

Yes, you mean:

B=sum(A,3)./sum(A~=0,3);

[A LL]

Thanks!

[Rik]

Yes, that is what I meant, thank you for correcting it.