Smoothing data with sgolay filter

Hi i have a question, if i have a code like this before,

smootheddata = smoothdata(z,"sgolay", "SmoothingFactor",0.25 );

how i exprese it in sgolay function ? Thank you

Answer 1

[Chunru]

framelen = 11; order = 3;   % adjust these values
smootheddata = sgolayfilt(z, order, framelen); 

Answer 2

[Star Strider]

The default order for the 'sgolay' option is 2 (quadratic), however the 'SmoothingFactor' controls the window length (framelen in the sgolayfilt documentation), it has no exact definition, so an exact translation to sgolayfilt parameters is not possible for it.

For sgolayfilt I generally choose an order of 3 and an initial framelen value of 5% of the signal length. I then adjust the framelen value to get the result I want. It is possible to control these in the smoothdata function by setting the 'Degree' and window parameters.