User`s guide

smooth
4-129
are given below. For the Savitzky-Golay method, the default polynomial degree
is 2.
yy = smooth(ydata,span,'method') smooths data using the specified span
and
method. For the loess and lowess methods, you can specify span as a
percentage of the total number of data points. In this case,
span must be less
than or equal to 1. For the moving average and Savitzky-Golay methods,
span
must be odd. If an even
span is specified, it is reduced by 1.
yy = smooth(ydata,'sgolay',degree) uses the Savitzky-Golay method with
polynomial degree specified by
degree.
yy = smooth(ydata,span,'sgolay',degree) uses the number of data points
specified by
span in the Savitzky-Golay calculation. span must be odd and
degree must be less than span.
yy = smooth(xdata,ydata,...) smooths the data specified by ydata and the
associated predictor data,
xdata. You should specify the predictor data when it
is not uniformly spaced or it is not sorted. If
xdata is not uniform and you do
not specify
method, lowess is used. If the smoothing method requires xdata to
be sorted, the sorting occurs automatically.
Method Description
moving
Moving average filter.
lowess Locally weighted scatter plot smooth using least squares
linear polynomial fitting.
loess Locally weighted scatter plot smooth using least squares
quadratic polynomial fitting.
sgolay Savitzky-Golay filter. Note that the algorithm used by the
toolbox can accept nonuniform predictor data.
rlowess Lowess smoothing that is resistant to outliers.
rloess Loess smoothing that is resistant to outliers.