Fillmissing & Smooth LOESS span

Hi,

I got my Data, matrix X. For column 2 for example, I got 4 sequences of NaN values. Instead of fillmissing by movmean all the length of X(:,2), I search for the 4 sequence of NaN values and for each, select a window to perform the movmean and only fill the NaN values.

Question 1) I would like to know if "spline" or "pchip" under the function fillmissing i can input a size window similar to movmean methodology?

Question 2) For making the smooth, i would like to know what the span is, because when I do

idx_time = [1:size(X,1)]';
Xsmooth = smooth(idx_time,X(:,2),0.01,'loess')

The span of 0.01 still result in NaN's, but 0.1 does all the fill to NaN sequence. I would like to know what to do to find the best span and if it is possible to calculate a span for each sequence for column 2. Sequence 1 has 4 NaNs (from 4 to 7), Sequence 2 has 2 NaNs (index 9 to 10), Sequence 3 has 2 NaNs (index 61 to 62), Sequence 4 has 2 NaNs (from 64 to 65).

Thanks for your help.