SmoothSignal

Declaration:

SmoothSignal(var Signal: TDoubleArray; Mode: TSpecSmoothMode; WindowSize: integer; SmoothPar1, SmoothPar2: double): integer;

Smoothes the data in the variable Signal. The parameter Mode specifies the type of smoothing: spsmMovAvg ... moving average spsmWgtAvg ... weighted moving average spsmPolynomial ... Savitzky-Golay polynomial smoothing spsmMovMed ... moving median spsmPenSpline ... penalized spline spsmSincBS ... sinc band-stop (convolved with a Blackman window) spsmSincBP ... sinc band-pass (convolved with a Blackman window) spsmSincLP ... sinc lowpass (convolved with a Blackman window) spsmSincHP ... sinc highpass (convolved with a Blackman window) spsmChebychevLP ... Chebychev lowpass filter The parameter WindowSize defines the size of the smoothing window in the case of the moving window algorithms (spsmMovAvg, spsmWgtAvg, spsmPolynomial, spsmMovMed) and must be an odd value. In the case of the penalized spline the WindowSize is irrelevant and ignored. For Chebychev filters it controls the number of poles and must be even (2..20). The parameters SmoothPar1 and SmoothPar2 have different meanings for the various filter modes: Mode SmoothPar1 SmoothPar2 spsmMovAvg, spsmWgtAvg, spsmPolynomial, spsmMovMed ignored ignored spsmPenSpline controls the stiffness of the spine valid range: 0.0 (no penalizing) to 1.0 (full penalizing) spsmSincBS, spsmSincBP cut-off frequency of the lower limit of the band as a fraction of the sampling frequency valid range: >0.0 to 0.5. cut-off frequency of the upper limit of the band as a fraction of the sampling frequency valid range: >0.0 to 0.5. spsmSincLP, spsmSincHP cut-off frequency as a fraction of the sampling frequency valid range: >0.0 to 0.5. ignored spsmChebychevLP cut-off frequency as a fraction of the sampling frequency valid range: >0.0 to 0.5. controls the percent ripple in the passband valid range: 0 to 29   The function returns the following error codes:  0 ... everything is OK -3 ... invalid Mode -4 ... WindowSize out of range -5 ... SmoothPar1 and/or SmoothPar2 out of range -6 ... WindowSize must be odd -7 ... WindowSize must be less than half of the spectral range -8 ... WindowSize must be even (Chebychev) -9 ... SmoothPar2 out of range (Chebychev: 0..29)