how can i perform the calculation of the span at smoothing?

Hello,

I have some doubts on how to select the span in order to smooth all my NaN values and values.

For example, I got:

A = [5;7;9;19;NaN;NaN;NaN;NaN;5;NaN;7;NaN]
idx = [1:size(A,1)]'
B = smooth(idx,A,4,'loess')

If I use the span of 2, 3 or 4 I have the value "0" in some NaN's, if I use the span of 5, I got everything smoothed right.

I would like to know if it is possible, before doing the smooth code line, how to perform a calculation of span to ensure that the result doesn't have nan's?

Thanks for your time.

[Al Alvino]

Hi Tiago,

Did you find a solution for your question? I have the same problem, how can i know what span value i should use in the smooth command.

Thanks

Alberto

[Tiago Dias]

I assume it is because in my index 6 the span (i think is the window he considers) i got more nans than numbers.

I would recomend to go to a moving window strategy, has matlab centers the index ( lets say index 5) and he goes 4 above and 4 below, if span is 4.

https://www.mathworks.com/help/matlab/ref/smoothdata.html

here some example