class CEntry
{
	public:

		double x;				// value stored in the entry
		int c;					// column that the entry lives in
		CEntry *next;			// pointer to next entry in row;
		CEntry();
		
	private:
};

#define LAMBDA 1.5

class CBigLinProb
{
	public:

		// data members	

		double *V;				// solution
		double *P;				// search direction;
		double *R;				// residual;
		double *U;				// A * P;
		double *Z;				
		double *b;				// RHS of linear equation
		CEntry **M;				// pointer to list of matrix entries;
		int n;					// dimensions of the matrix;
		int bdw;				// Optional matrix bandwidth parameter;
		double Precision;		// error tolerance for solution

		// member functions

		CBigLinProb();				// constructor
		~CBigLinProb();				// destructor
		int Create(int d, int bw);			// initialize the problem
		void Put(double v, int p, int q);
									// use to create/set entries in the matrix
		double Get(int p, int q);
		void AddTo(double v, int p, int q);
		int PCGSolve(int flag);		 // flag==true if guess for V present;
		void MultPC(double *X, double *Y);
		void MultA(double *X, double *Y);
		void SetValue(int i, double x);
		void Periodicity(int i, int j);
		void AntiPeriodicity(int i, int j);
		void Wipe();
		double Dot(double *X, double *Y);
		void ComputeBandwidth();

		CFknDlg *TheView;

	private:

};


/////////////////////////////////////////////////////////////////////
// for complex matrices......

class CComplexEntry
{
	public:

		CComplex x;				// value stored in the entry
		int c;					// column that the entry lives in
		CComplexEntry *next;	// pointer to next entry in the row;
		CComplexEntry();
		
	private:
};

class CBigComplexLinProb
{
	public:

		// data members	

		CComplex *P; 				// search direction
		CComplex *U;
	 	CComplex *R; 				// residual
		CComplex *V; 
		CComplex *Z;		
		CComplex *b;				// RHS of linear equation
		CComplex *uu;
		CComplex *vv;

		CComplexEntry **M;			// pointer to list of matrix entries;
		CComplexEntry **Mh;			// Hermitian matrix arising from N-R algorithm;
		CComplexEntry **Ma;			// Antihermitian matrix arising from N-R algorithm;
		CComplexEntry **Ms;			// Additional complex-symmetric matrix arising from N-R algorithm;
		int n;						// dimensions of the matrix;
		int bdw;					// optional bandwidth parameter;
		int bNewton;				// Flag which denotes whether or not there are entries in Mh or Ms;
		int NumNodes;
		double Precision;

		// member functions

		CBigComplexLinProb();				// constructor
		~CBigComplexLinProb();				// destructor
		int Create(int d, int bw, int nodes);	// initialize the problem
		void Put(CComplex v, int p, int q, int k=0); // use to create/set entries in the matrix
		CComplex Get(int p, int q, int k=0);
		void AddTo(CComplex v, int p, int q);
		void MultA(CComplex *X, CComplex *Y, int k=0);
		void MultConjA(CComplex *X, CComplex *Y, int k=0);
		CComplex Dot(CComplex *x, CComplex *y);
		CComplex ConjDot(CComplex *x, CComplex *y);
		void SetValue(int i, CComplex x);
		void Periodicity(int i, int j);
		void AntiPeriodicity(int i, int j);
		void Wipe();
		void MultPC(CComplex *X, CComplex *Y);
		void MultAPPA(CComplex *X, CComplex *Y);


		// flag==false initializes solution to zero
		// flag==true  starts from solution of previous call
		int PBCGSolveMod(int flag);	// Precondition Biconjugate Gradient
		int PCGSQStart();
		int PBCGSolve(int flag);	
		int BiCGSTAB(int flag);
		int KludgeSolve(int flag);

		CFknDlg *TheView;

	private:

};