autocov is initialized NaN with the original order and then only loop up to...

autocov is initialized NaN with the original order and then only loop up to updted order compatible with sample size.

matlab/utilities/dataset/nanautocovariance.m

@@ -55,8 +55,9 @@ function autocov = nanautocovariance(data,order)
 
 n = size(data,2);
 missing = isanynan(data);
+autocov = nan(n, n, order);
 order = min(size(data,1)-2,order);
-autocov = zeros(n, n, order);
+autocov(:, :, 1:order)=0;
 
 for lag=1:order
     if missing