CATCurveFit.h

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/// \file CATCurveFit.h
/// \brief Fit a curve to a set of points
/// \ingroup CAT
///
/// Copyright (c) 2002-2008 by Michael Ellison.
/// See COPYING.txt for the \ref gaslicense License (MIT License).
///
// $Author: mikeellison $
// $Date: 2008-01-19 19:19:35 -0600 (Sat, 19 Jan 2008) $
// $Revision:   $
// $NoKeywords: $

#ifndef _CATCURVEFIT_H_
#define _CATCURVEFIT_H_

#include "CATInternal.h"
#include "CATPoint.h"
#include "CATMatrix.h"

/// \class CATCurveFit
/// \brief  Fit a curve to a set of points
/// \ingroup CAT
///
/// Fits a curve of the specified degree to a set of data.
/// Based off the algorithm presented in "Introduction to Algorithms" Second Edition,
///    by Cormen, Leiserson, Rivest, and Stein (MIT press)
///
class CATCurveFit
{
    public:     
        /// Pass in the number of coefficients you want to calculate.
        /// defaults to quadratic.  For line, use 2.
        CATCurveFit(CATUInt32 curveDegree = 3);

        virtual ~CATCurveFit();

        /// Add a point to the interpolation data
        bool        AddPoint( CATFloat64 x, CATFloat64 y);

        /// Clear out all current data
        bool        Clear();
        
        /// Get the polynomial degree
        bool        GetDegree(CATUInt32 &degree);

        /// Get a specific coefficient
        bool        GetCoefficient( CATUInt32 deg, CATFloat64& coef);
        
        /// Get the number of data points acquired
        CATUInt32   GetNumPoints();

        /// Get an individual data point
        bool        GetDataPoint( CATUInt32 n, CATFloat64& x, CATFloat64& y);
        
        /// Calculate the Y val from a specified x val
        bool        CalcYVal( CATFloat64 x, CATFloat64& y);

        /// Get error value
        bool        GetCurrentErr( CATFloat64& err);

        bool        GetMinMax( CATFloat64& minX, CATFloat64& minY, CATFloat64& maxX, CATFloat64& maxY);

        bool        LangrangianCalcY(CATFloat64 x, CATFloat64 &y);
    protected:      
        bool        CalcFit();  // Internal calc    
        
        std::vector <CATPoint> fPointList; ///< list of X points
        std::vector <CATFloat64> fCoef;    ///< list of coefficients (double's)     
        
        CATFloat64  fLastErr;              ///< last calculated err

        CATUInt32   fDegree;               ///< Degree of coefficient to calculate with fit
                
        bool        fDirty;                ///< Are the coefficients dirty? (i.e. need to call CalcFit?)
};

#endif // _CATCURVEFIT_H_

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