// @(#)root/hist:$Name: $:$Id: TF3.cxx,v 1.2 2000/06/13 10:38:11 brun Exp $
// Author: Rene Brun 27/10/95
/*************************************************************************
* Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *
* All rights reserved. *
* *
* For the licensing terms see $ROOTSYS/LICENSE. *
* For the list of contributors see $ROOTSYS/README/CREDITS. *
*************************************************************************/
#include "TROOT.h"
#include "TF3.h"
#include "TMath.h"
#include "TH3.h"
#include "TVirtualPad.h"
#include "TRandom.h"
ClassImp(TF3)
//______________________________________________________________________________
//
// a 3-Dim function with parameters
//
//______________________________________________________________________________
TF3::TF3(): TF2()
{
//*-*-*-*-*-*-*-*-*-*-*F3 default constructor*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
//*-* ======================
}
//______________________________________________________________________________
TF3::TF3(const char *name,const char *formula, Double_t xmin, Double_t xmax, Double_t ymin, Double_t ymax, Double_t zmin, Double_t zmax)
:TF2(name,formula,xmin,xmax,ymin,ymax)
{
//*-*-*-*-*-*-*F3 constructor using a formula definition*-*-*-*-*-*-*-*-*-*-*
//*-* =========================================
//*-*
//*-* See TFormula constructor for explanation of the formula syntax.
//*-*
//*-*
//*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
fZmin = zmin;
fZmax = zmax;
fNpz = 30;
}
//______________________________________________________________________________
TF3::TF3(const char *name,void *fcn, Double_t xmin, Double_t xmax, Double_t ymin, Double_t ymax, Double_t zmin, Double_t zmax, Int_t npar)
:TF2(name,fcn,xmin,xmax,ymin,ymax,npar)
{
//*-*-*-*-*-*-*F3 constructor using a pointer to an interpreted function*-*-*
//*-* =========================================================
//*-*
//*-* npar is the number of free parameters used by the function
//*-*
//*-* Creates a function of type C between xmin and xmax and ymin,ymax.
//*-* The function is defined with npar parameters
//*-* fcn must be a function of type:
//*-* Double_t fcn(Double_t *x, Double_t *params)
//*-*
//*-* This constructor is called for functions of type C by CINT.
//*-*
//*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
fZmin = zmin;
fZmax = zmax;
fNpz = 30;
fNdim = 3;
}
//______________________________________________________________________________
TF3::TF3(const char *name,Double_t (*fcn)(Double_t *, Double_t *), Double_t xmin, Double_t xmax, Double_t ymin, Double_t ymax, Double_t zmin, Double_t zmax, Int_t npar)
:TF2(name,fcn,xmin,xmax,ymin,ymax,npar)
{
//*-*-*-*-*-*-*F3 constructor using a pointer to real function*-*-*-*-*-*-*-*
//*-* ===============================================
//*-*
//*-* npar is the number of free parameters used by the function
//*-*
//*-* For example, for a 3-dim function with 3 parameters, the user function
//*-* looks like:
//*-* Double_t fun1(Double_t *x, Double_t *par)
//*-* return par[0]*x[2] + par[1]*exp(par[2]*x[0]*x[1]);
//*-*
//*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
fZmin = zmin;
fZmax = zmax;
fNpz = 30;
fNdim = 3;
}
//______________________________________________________________________________
TF3::~TF3()
{
//*-*-*-*-*-*-*-*-*-*-*F3 default destructor*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
//*-* =====================
}
//______________________________________________________________________________
TF3::TF3(const TF3 &f3)
{
((TF3&)f3).Copy(*this);
}
//______________________________________________________________________________
void TF3::Copy(TObject &obj)
{
//*-*-*-*-*-*-*-*-*-*-*Copy this F3 to a new F3*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
//*-* ========================
TF2::Copy(obj);
((TF3&)obj).fZmin = fZmin;
((TF3&)obj).fZmax = fZmax;
((TF3&)obj).fNpz = fNpz;
}
//______________________________________________________________________________
Int_t TF3::DistancetoPrimitive(Int_t px, Int_t py)
{
//*-*-*-*-*-*-*-*-*-*-*Compute distance from point px,py to a function*-*-*-*-*
//*-* ===============================================
//*-* Compute the closest distance of approach from point px,py to this function.
//*-* The distance is computed in pixels units.
//*-*
//*-* Algorithm:
//*-*
//*-*
//*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
return TF1::DistancetoPrimitive(px, py);
}
//______________________________________________________________________________
void TF3::Draw(Option_t *option)
{
//*-*-*-*-*-*-*-*-*-*-*Draw this function with its current attributes*-*-*-*-*
//*-* ==============================================
TString opt = option;
opt.ToLower();
if (!opt.Contains("s")) gPad->Clear();
AppendPad(option);
}
//______________________________________________________________________________
void TF3::ExecuteEvent(Int_t event, Int_t px, Int_t py)
{
//*-*-*-*-*-*-*-*-*-*-*Execute action corresponding to one event*-*-*-*
//*-* =========================================
//*-* This member function is called when a F3 is clicked with the locator
//*-*
//*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
TF1::ExecuteEvent(event, px, py);
}
//______________________________________________________________________________
void TF3::GetRandom3(Double_t &xrandom, Double_t &yrandom, Double_t &zrandom)
{
//*-*-*-*-*-*Return 3 random numbers following this function shape*-*-*-*-*-*
//*-* =====================================================
//*-*
//*-* The distribution contained in this TF3 function is integrated
//*-* over the cell contents.
//*-* It is normalized to 1.
//*-* Getting the three random numbers implies:
//*-* - Generating a random number between 0 and 1 (say r1)
//*-* - Look in which cell in the normalized integral r1 corresponds to
//*-* - make a linear interpolation in the returned cell
//*-*
// Check if integral array must be build
Int_t i,j,k,cell;
Double_t dx = (fXmax-fXmin)/fNpx;
Double_t dy = (fYmax-fYmin)/fNpy;
Double_t dz = (fZmax-fZmin)/fNpz;
Int_t ncells = fNpx*fNpy*fNpz;
Double_t xx[3];
InitArgs(xx,fParams);
if (fIntegral == 0) {
fIntegral = new Double_t[ncells+1];
fIntegral[0] = 0;
Double_t integ;
Int_t intNegative = 0;
cell = 0;
for (k=0;k<fNpz;k++) {
xx[2] = fZmin+(k+0.5)*dz;
for (j=0;j<fNpy;j++) {
xx[1] = fYmin+(j+0.5)*dy;
for (i=0;i<fNpx;i++) {
xx[0] = fXmin+(i+0.5)*dx;
integ = EvalPar(xx,fParams);
if (integ < 0) {intNegative++; integ = -integ;}
fIntegral[cell+1] = fIntegral[cell] + integ;
cell++;
}
}
}
if (intNegative > 0) {
Warning("GetRandom3","function:%s has %d negative values: abs assumed",GetName(),intNegative);
}
if (fIntegral[ncells] == 0) {
Error("GetRandom3","Integral of function is zero");
return;
}
for (i=1;i<=ncells;i++) { // normalize integral to 1
fIntegral[i] /= fIntegral[ncells];
}
}
// return random numbers
Double_t r;
r = gRandom->Rndm();
cell = TMath::BinarySearch(ncells,fIntegral,r);
k = cell/(fNpx*fNpy);
j = (cell -k*fNpx*fNpy)/fNpx;
i = cell -fNpx*(j +fNpy*k);
xrandom = fXmin +dx*i +dx*gRandom->Rndm();
yrandom = fYmin +dy*j +dy*gRandom->Rndm();
zrandom = fZmin +dz*k +dz*gRandom->Rndm();
}
//______________________________________________________________________________
void TF3::GetRange(Double_t &xmin, Double_t &ymin, Double_t &zmin, Double_t &xmax, Double_t &ymax, Double_t &zmax)
{
//*-*-*-*-*-*-*-*-*-*-*Return range of function*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
//*-* ========================
xmin = fXmin;
xmax = fXmax;
ymin = fYmin;
ymax = fYmax;
zmin = fZmin;
zmax = fZmax;
}
//______________________________________________________________________________
Double_t TF3::Integral(Double_t ax, Double_t bx, Double_t ay, Double_t by, Double_t az, Double_t bz, Double_t epsilon)
{
// Return Integral of a 3d function in range [ax,bx],[ay,by],[az,bz]
//
Double_t a[3], b[3];
a[0] = ax;
b[0] = bx;
a[1] = ay;
b[1] = by;
a[2] = az;
b[2] = bz;
Double_t relerr = 0;
Double_t result = IntegralMultiple(3,a,b,epsilon,relerr);
return result;
}
//______________________________________________________________________________
void TF3::Paint(Option_t *)
{
//*-*-*-*-*-*-*-*-*Paint this 2-D function with its current attributes*-*-*-*-*
//*-* ===================================================
}
//______________________________________________________________________________
void TF3::SetNpz(Int_t npz)
{
//*-*-*-*-*-*-*-*Set the number of points used to draw the function*-*-*-*-*-*
//*-* ==================================================
if(npz > 4 && npz < 1000) fNpz = npz;
Update();
}
//______________________________________________________________________________
void TF3::SetRange(Double_t xmin, Double_t ymin, Double_t zmin, Double_t xmax, Double_t ymax, Double_t zmax)
{
//*-*-*-*-*-*Initialize the upper and lower bounds to draw the function*-*-*-*
//*-* ==========================================================
fXmin = xmin;
fXmax = xmax;
fYmin = ymin;
fYmax = ymax;
fZmin = zmin;
fZmax = zmax;
Update();
}
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