SavitzkyGolayFilter Class

Class SavitzkyGolayFilter is a correlation filter specialized for filtering with Savitzky-Golay coefficients with additional boundary options for better edge continuity. The default boundary option ShiftFilterCenter provides data smoothing all the way boundary ends.

Inheritance Hierarchy

SystemObject
CenterSpace.NMath.CoreCorrelationFilter
CenterSpace.NMath.CoreSavitzkyGolayFilter

Namespace: CenterSpace.NMath.Core
Assembly: NMath (in NMath.dll) Version: 7.4

Syntax

C++

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[SerializableAttribute]
public class SavitzkyGolayFilter : CorrelationFilter, 
	ICloneable

<SerializableAttribute>
Public Class SavitzkyGolayFilter
	Inherits CorrelationFilter
	Implements ICloneable

[SerializableAttribute]
public ref class SavitzkyGolayFilter : public CorrelationFilter, 
	ICloneable

[<SerializableAttribute>]
type SavitzkyGolayFilter = 
    class
        inherit CorrelationFilter
        interface ICloneable
    end

The SavitzkyGolayFilter type exposes the following members.

Constructors

	Name	Description
	SavitzkyGolayFilter	Constructs a C# Copy SavitzkyGolayFilter for smoothing using Savitzky-Golay coefficients. This creates a filter of width five using a third order smoothing polynomial.
	SavitzkyGolayFilter(Int32)	Constructs a C# Copy SavitzkyGolayFilter for smoothing using Savitzky-Golay coefficients. This creates a filter of width of five.
	SavitzkyGolayFilter(Int32, Int32, Int32)	Constructs a C# Copy SavitzkyGolayFilter for data smoothing using Savitzky-Golay coefficients fitted to a polynomial of order C# Copy polynomialOrder .
	SavitzkyGolayFilter(Int32, Int32, Int32, Int32)	Constructs a C# Copy SavitzkyGolayFilter instance which implements a correlation filter using Savitzky-Golay coefficients. Either the data or a derivative of C# Copy derivativeOrder of the data can be smoothed.

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Properties

	Name	Description
	BoundaryOption	Gets/Sets the current boundary option.
	NumberLeft	Gets the number of points left of the filtering window center point.
	NumberOfCoefficients	Gets the number of filter coefficients. Effectively the filter width. (Inherited from CorrelationFilter)
	NumberRight	Gets the number of points right of the filtering window center point.
	WindowWidth	Gets the width of the moving window.

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Methods

	Name	Description
	Clone	Creates a deep copy of this SavitzkyGolayFilter instance.
	Correlate	Does the correlation and takes care of internal correlation and work objects. (Inherited from CorrelationFilter)
	Filter(DoubleVector)	Filters C# Copy data using the current boundary option. (Overrides CorrelationFilterFilter(DoubleVector))
	Filter(DoubleVector, DoubleVector)	Filters C# Copy data using the current boundary option. (Overrides CorrelationFilterFilter(DoubleVector, DoubleVector))
	ScaleDerivative	Scales raw Savitzky-Golay derivatives given the abscissa step size.

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Fields

	Name	Description
	coefficients_	Filtering coefficients for correlation operation. (Inherited from CorrelationFilter)
	work_	Provides a working vector for correlation results. (Inherited from CorrelationFilter)

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Remarks

The width of the filter is: numberLeft + numberRight + 1. Note that smoothing boundaries requires significantly more computational effort than zero padding. The current boundary option can be set using the

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BoundaryOption

property.

Example

SavitzkyGolayFilter sgf = new SavitzkyGolayFilter(2, 2, 3, 0); // Width 5, Polynomial degree 3 sgf.BoundaryOption = SavitzkyGolayFilter.SavitzyGolayBoundaryOptions.DoNotFilterBoundaryPoints; DoubleVector x = new DoubleVector(2, 1, 1, 3, 1, 1, 2); DoubleVector z = sgf.Filter(x);

Reference

CenterSpace.NMath.Core Namespace