#ifndef CompFrcStructs
#define CompFrcStructs

/***=======================================================================***/
/*** CubicSpline: this structure holds coefficients for a piecewise cubic  ***/
/***              spline approximation of some real-valued function of one ***/
/***              variable.  An array of these structs forms the complete  ***/
/***              approximation over some range of the variable:           ***/
/***                                                                       ***/
/***              f(x) = Ax^3 + Bx^2 + Cx + D                              ***/
/***=======================================================================***/
struct CubicSpline {
  double A;
  double B;
  double C;
  double D;
};
typedef struct CubicSpline CSpln;

/***=======================================================================***/
/*** ForceTable: this structure holds a force (and energy) piecewise cubic ***/
/***             spline table.                                             ***/
/***=======================================================================***/
struct ForceTable {

  /*** Attributes needed for force and energy evaluation ***/
  int nbin;
  double rmax;
  double dr;
  double ivdr;
  CSpln* SD;
  CSpln* dSD;

  /*** Error analysis ***/
  int FitType;            // The type of spline interpolation
                          //   0: best fit at intervals 0, 1/3, 2/3, 1, ...
                          //   1: fit with continuous direvatives at 0, 1, ...
  double fmaxerr;         // Maximum absolute error in the derivative (force)
  double fmaxerrloc;      // Location of the maximum error in the derivative
  double fmaxrelerr;      // Maximum relative error in the derivative
  double fmaxrelerrloc;   // Location of maximum relative error...
  double umaxerr;         // Maximum absolute error in the function (potential)
  double umaxerrloc;      // Location of the maximum error in the function
  double umaxrelerr;      // Maximum relative error in the function
  double umaxrelerrloc;   // Location of maximum relative error in the function
};
typedef struct ForceTable FrcTab;

#endif