BSplineBase.h

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/************************************************************************
 * Copyright 2009 University Corporation for Atmospheric Research.
 * All rights reserved.
 *
 * Use of this code is subject to the standard BSD license:
 *
 *  http://www.opensource.org/licenses/bsd-license.html
 *
 * See the COPYRIGHT file in the source distribution for the license text,
 * or see this web page:
 *
 *  http://www.eol.ucar.edu/homes/granger/bspline/doc/
 *
 *************************************************************************/
#ifndef BSPLINEBASE_H_
#define BSPLINEBASE_H_

#ifndef _BSPLINEBASE_IFACE_ID
#define _BSPLINEBASE_IFACE_ID "$Id: BSpline.h 6353 2008-05-05 19:30:48Z martinc $"
#endif

template <class T> class BSpline;

/*
 * Opaque member structure to hide the matrix implementation.
 */
template <class T> struct BSplineBaseP;

template <class T> 
class BSplineBase  
{
public:
    // Datum type
    typedef T datum_type;

    static const char *ImplVersion();

    static const char *IfaceVersion();
    
    static bool Debug (int on = -1);

    enum BoundaryConditionTypes
    {
    BC_ZERO_ENDPOINTS = 0,
    BC_ZERO_FIRST = 1,
    BC_ZERO_SECOND = 2
    };

public:

    BSplineBase (const T *x, int nx, 
         double wl, int bc_type = BC_ZERO_SECOND,
         int num_nodes = 0);

    BSplineBase (const BSplineBase &);

    bool setDomain (const T *x, int nx, double wl, 
            int bc_type = BC_ZERO_SECOND,
            int num_nodes = 0);

    BSpline<T> *apply (const T *y);

    const T *nodes (int *nnodes);

    int nNodes () { return M+1; }

    int nX () { return NX; }

    T Xmin () { return xmin; }

    T Xmax () { return xmin + (M * DX); }

    double Alpha (double wavelength);

    double Alpha () { return alpha; }

    bool ok () { return OK; }

    virtual ~BSplineBase();

protected:

    typedef BSplineBaseP<T> Base;

    // Provided
    double waveLength;  // Cutoff wavelength (l sub c)
    int NX;
    int K;  // Degree of derivative constraint (currently fixed at 2)
    int BC;         // Boundary conditions type (0,1,2)

    // Derived
    T xmax;
    T xmin;
    int M;          // Number of intervals (M+1 nodes)
    double DX;          // Interval length in same units as X
    double alpha;
    bool OK;
    Base *base;         // Hide more complicated state members
                    // from the public interface.

    bool Setup (int num_nodes = 0);
    void calculateQ ();
    double qDelta (int m1, int m2);
    double Beta (int m);
    void addP ();
    bool factor ();
    double Basis (int m, T x);
    double DBasis (int m, T x);

    static const double BoundaryConditions[3][4];
    static const double PI;

    double Ratiod (int&, double &, double &);
};

#endif /*BSPLINEBASE_H_*/