MATLAB: Kurtosis ignoring 0s in matrix

kurtosis

Hi there, I was wondering I have a matrix A of size 295×34. I want to do the kurtosis, but want to ignore all zeros.

How can I do this?

out = cellfun(@(x)kurtosis(x(x~=0)),num2cell(A,1));

s = sum(A~=0);
x1 = bsxfun(@minus,A,sum(A)./s);
x1(A == 0) = 0;
out = s.*sum(x1.^4)./ sum(x1.^2).^2;

syms x1 x2
X = [1, x1, x2, x1^2, x2^2, x1*x2], 
out=char(X(1))
for k=2:numel(X)
  out=[out  '+'  char(X(k))]
end

One easy way would be to convert all zeros to NaN, and then use the nanstd function to ignore the NaNs in the std calculation.

Absy(Absy==0)=NaN;
s = nanstd(Absy,[],1);   %column by column std deviation