genie::BLI2DUnifGrid Class Reference

Bilinear interpolation of 2D functions on a regular grid. More...

#include <BLI2D.h>

Inheritance diagram for genie::BLI2DUnifGrid:

Public Member Functions
	BLI2DUnifGrid ()
	BLI2DUnifGrid (int nx, double xmin, double xmax, int ny, double ymin, double ymax)
	BLI2DUnifGrid (int nx, int ny, double *x, double *y, double *z)
bool	AddPoint (double x, double y, double z)
double	Evaluate (double x, double y) const
Public Member Functions inherited from genie::BLI2DGrid
	BLI2DGrid ()
virtual	~BLI2DGrid ()
double	XMin (void) const
double	XMax (void) const
double	YMin (void) const
double	YMax (void) const
double	ZMin (void) const
double	ZMax (void) const

Private Member Functions
void	Init (int nx=0, double xmin=0, double xmax=0, int ny=0, double ymin=0, double ymax=0)

Additional Inherited Members
Protected Member Functions inherited from genie::BLI2DGrid
int	IdxZ (int ix, int iy) const
Protected Attributes inherited from genie::BLI2DGrid
int	fNX
int	fNY
int	fNZ
double *	fX
double *	fY
double *	fZ
double	fDX
double	fDY
double	fXmin
double	fXmax
double	fYmin
double	fYmax
double	fZmin
double	fZmax

Detailed Description

Bilinear interpolation of 2D functions on a regular grid.

Author

Costas Andreopoulos <constantinos.andreopoulos cern.ch> University of Liverpool & STFC Rutherford Appleton Laboratory

May 30, 2009

Copyright (c) 2003-2020, The GENIE Collaboration For the full text of the license visit http://copyright.genie-mc.org

Definition at line 75 of file BLI2D.h.

Constructor & Destructor Documentation

genie::BLI2DUnifGrid::BLI2DUnifGrid

(

)

BLI2DUnifGrid::BLI2DUnifGrid	(	int	nx,
		double	xmin,
		double	xmax,
		int	ny,
		double	ymin,
		double	ymax
	)

Definition at line 50 of file BLI2D.cxx.

{
  this->Init(nx, xmin, xmax, ny, ymin, ymax);
}

BLI2DUnifGrid::BLI2DUnifGrid	(	int	nx,
		int	ny,
		double *	x,
		double *	y,
		double *	z
	)

Definition at line 56 of file BLI2D.cxx.

{
  double xmin = x[0];
  double xmax = x[nx-1];
  double ymin = y[0];
  double ymax = y[nx-1];

  this->Init(nx, xmin, xmax, ny, ymin, ymax);

  for(int ix=0; ix<nx; ix++) {
    for(int iy=0; iy<ny; iy++) {
      this->AddPoint(x[ix], y[iy], z[this->IdxZ(ix,iy)]);
    }
  }
}

Member Function Documentation

bool BLI2DUnifGrid::AddPoint ( double  x, double  y, double  z  )

virtual

Implements genie::BLI2DGrid.

Definition at line 73 of file BLI2D.cxx.

{
  int ix = TMath::FloorNint( (x - fXmin + fDX/2) / fDX );
  int iy = TMath::FloorNint( (y - fYmin + fDY/2) / fDY );
  int iz = this->IdxZ(ix,iy);

  fZ[iz] = z;

  fZmin = TMath::Min(z, fZmin);
  fZmax = TMath::Max(z, fZmax);

  LOG("BLI2DUnifGrid", pDEBUG)
    << "Added x = " << x << " (ix = " << ix << ")"
         << " y = " << y << " (iy = " << iy << ") -> "
         << " z = " << z << " (iz = " << iz << ")";

  return true;
}

double BLI2DUnifGrid::Evaluate ( double  x, double  y  ) const

virtual

Implements genie::BLI2DGrid.

Definition at line 92 of file BLI2D.cxx.

{
  if(x < fXmin || x > fXmax) return 0.;
  if(y < fYmin || y > fYmax) return 0.;

  int ix_lo  = TMath::FloorNint( (x - fXmin) / fDX );
  int iy_lo  = TMath::FloorNint( (y - fYmin) / fDY );
  int ix_hi  = ix_lo + 1;
  int iy_hi  = iy_lo + 1;

  double x1  = fX[ix_lo];
  double x2  = fX[ix_hi];
  double y1  = fY[iy_lo];
  double y2  = fY[iy_hi];

  double z11 = fZ[ this->IdxZ(ix_lo,iy_lo) ];
  double z21 = fZ[ this->IdxZ(ix_hi,iy_lo) ];
  double z12 = fZ[ this->IdxZ(ix_lo,iy_hi) ];
  double z22 = fZ[ this->IdxZ(ix_hi,iy_hi) ];

  double z1  = z11 * (x2-x)/(x2-x1) + z21 * (x-x1)/(x2-x1);
  double z2  = z12 * (x2-x)/(x2-x1) + z22 * (x-x1)/(x2-x1);
  double z   = z1  * (y2-y)/(y2-y1) + z2  * (y-y1)/(y2-y1);

/*
  LOG("BLI2DUnifGrid", pDEBUG) << "x = " << x << " -> nearby nodes: " << x1 << ", " << x2;
  LOG("BLI2DUnifGrid", pDEBUG) << "y = " << y << " -> nearby nodes: " << y1 << ", " << y2;
  LOG("BLI2DUnifGrid", pDEBUG) << "z11 := z(" << this->IdxZ(ix_lo,iy_lo) << ")  = " << z11;
  LOG("BLI2DUnifGrid", pDEBUG) << "z21 := z(" << this->IdxZ(ix_hi,iy_lo) << ")  = " << z21;
  LOG("BLI2DUnifGrid", pDEBUG) << "z12 := z(" << this->IdxZ(ix_lo,iy_hi) << ")  = " << z12;
  LOG("BLI2DUnifGrid", pDEBUG) << "z22 := z(" << this->IdxZ(ix_hi,iy_hi) << ")  = " << z22;
  LOG("BLI2DUnifGrid", pDEBUG) << "z1 = " << z1 << ", z2 = " << z2;
  LOG("BLI2DUnifGrid", pDEBUG) << "interpolated z(x,y) = " << z;
*/

  return z;
}

void BLI2DUnifGrid::Init ( int  nx = 0, double  xmin = 0, double  xmax = 0, int  ny = 0, double  ymin = 0, double  ymax = 0  )

privatevirtual

Implements genie::BLI2DGrid.

Definition at line 130 of file BLI2D.cxx.

{
  fNX   = 0;
  fNY   = 0;
  fNZ   = 0;
  fXmin = 0.;
  fXmax = 0.;
  fYmin = 0.;
  fYmax = 0.;
  fZmin = std::numeric_limits<double>::max();
  fZmax = std::numeric_limits<double>::min();
  fDX   = 0.;
  fDY   = 0.;
  fX    = 0;
  fY    = 0;
  fZ    = 0;

  if(nx>1 && ny>1) {
    fNX = nx;
    fNY = ny;
    fNZ = nx * ny;

    fXmin = xmin;
    fXmax = xmax;
    fYmin = ymin;
    fYmax = ymax;
    fZmin = std::numeric_limits<double>::max();
    fZmax = std::numeric_limits<double>::min();

    fDX = (xmax-xmin)/(nx-1);
    fDY = (ymax-ymin)/(ny-1);

    fX = new double[fNX];
    fY = new double[fNY];
    fZ = new double[fNZ];

    for(int i=0; i<fNX; i++) { fX[i] = xmin + i*fDX; }
    for(int i=0; i<fNY; i++) { fY[i] = ymin + i*fDY; }
    for(int i=0; i<fNZ; i++) { fZ[i] = 0.; }
  }
}

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The documentation for this class was generated from the following files:

• Generator/src/Framework/Numerical/BLI2D.h
• Generator/src/Framework/Numerical/BLI2D.cxx