3 /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * See cxx source for full Copyright notice */
8 // Author: ruben.shahoyan@cern.ch 09/09/2006
10 ////////////////////////////////////////////////////////////////////////////////
12 // AliCheb3D produces the interpolation of the user 3D->NDimOut arbitrary //
13 // function supplied in "void (*fcn)(float* inp,float* out)" format //
14 // either in a separate macro file or as a function pointer. //
15 // Only coefficients needed to guarantee the requested precision are kept. //
17 // The user-callable methods are: //
18 // To create the interpolation use: //
19 // AliCheb3D(const char* funName, // name of the file with user function //
21 // AliCheb3D(void (*ptr)(float*,float*),// pointer on the user function //
22 // Int_t DimOut, // dimensionality of the function's output //
23 // Float_t *bmin, // lower 3D bounds of interpolation domain //
24 // Float_t *bmax, // upper 3D bounds of interpolation domain //
25 // Int_t *npoints, // number of points in each of 3 input //
26 // // dimension, defining the interpolation grid //
27 // Float_t prec=1E-6); // requested max.absolute difference between //
28 // // the interpolation and any point on grid //
30 // To test obtained parameterization use the method //
31 // TH1* TestRMS(int idim,int npoints = 1000,TH1* histo=0); //
32 // it will compare the user output of the user function and interpolation //
33 // for idim-th output dimension and fill the difference in the supplied //
34 // histogram. If no histogram is supplied, it will be created. //
36 // To save the interpolation data: //
37 // SaveData(const char* filename, Bool_t append ) //
38 // write text file with data. If append is kTRUE and the output file already //
39 // exists, data will be added in the end of the file. //
40 // Alternatively, SaveData(FILE* stream) will write the data to //
41 // already existing stream. //
43 // To read back already stored interpolation use either the constructor //
44 // AliCheb3D(const char* inpFile); //
45 // or the default constructor AliCheb3D() followed by //
46 // AliCheb3D::LoadData(const char* inpFile); //
48 // To compute the interpolation use Eval(float* par,float *res) method, with //
49 // par being 3D vector of arguments (inside the validity region) and res is //
50 // the array of DimOut elements for the output. //
52 // If only one component (say, idim-th) of the output is needed, use faster //
53 // Float_t Eval(Float_t *par,int idim) method. //
55 // void Print(option="") will print the name, the ranges of validity and //
56 // the absolute precision of the parameterization. Option "l" will also print //
57 // the information about the number of coefficients for each output //
60 // NOTE: during the evaluation no check is done for parameter vector being //
61 // outside the interpolation region. If there is such a risk, use //
62 // Bool_t IsInside(float *par) method. Chebyshev parameterization is not //
63 // good for extrapolation! //
65 // For the properties of Chebyshev parameterization see: //
66 // H.Wind, CERN EP Internal Report, 81-12/Rev. //
68 ////////////////////////////////////////////////////////////////////////////////
73 #include <TMethodCall.h>
76 #include <TObjArray.h>
83 // to decrease the compilable code size comment this define. This will exclude the routines
84 // used for the calculation and saving of the coefficients.
85 // #define _INC_CREATION_ALICHEB3D_
87 class AliCheb3DCalc: public TNamed
91 AliCheb3DCalc(FILE* stream); // read coefs from text file
92 ~AliCheb3DCalc() {Clear();}
94 void Print(Option_t* opt="") const;
95 void LoadData(FILE* stream);
96 Float_t Eval(Float_t *par) const;
98 #ifdef _INC_CREATION_ALICHEB3D_
99 void SaveData(const char* outfile,Bool_t append=kFALSE) const;
100 void SaveData(FILE* stream=stdout) const;
103 static void ReadLine(TString& str,FILE* stream);
107 void Clear(Option_t* option = "");
109 Float_t ChebEval1D(Float_t x, const Float_t * array, int ncf) const;
110 void InitRows(int nr);
111 void InitCols(int nc);
112 void InitElemBound2D(int ne);
113 void InitCoefs(int nc);
114 Int_t* GetNColsAtRow() const {return fNColsAtRow;}
115 Int_t* GetColAtRowBg() const {return fColAtRowBg;}
116 Int_t* GetCoefBound2D0() const {return fCoefBound2D0;}
117 Int_t* GetCoefBound2D1() const {return fCoefBound2D1;}
118 Float_t * GetCoefs() const {return fCoefs;}
121 Int_t fNCoefs; // total number of coeeficients
122 Int_t fNRows; // number of significant rows in the 3D coeffs matrix
123 Int_t fNCols; // max number of significant cols in the 3D coeffs matrix
124 Int_t fNElemBound2D; // number of elements (fNRows*fNCols) to store for the 2D boundary of significant coeffs
125 Int_t* fNColsAtRow; //[fNRows] number of sighificant columns (2nd dim) at each row of 3D coefs matrix
126 Int_t* fColAtRowBg; //[fNRows] beginnig of significant columns (2nd dim) for row in the 2D boundary matrix
127 Int_t* fCoefBound2D0; //[fNElemBound2D] 2D matrix defining the boundary of significance for 3D coeffs.matrix (Ncoefs for col/row)
128 Int_t* fCoefBound2D1; //[fNElemBound2D] 2D matrix defining the start beginnig of significant coeffs for col/row
129 Float_t * fCoefs; //[fNCoefs] array of Chebyshev coefficients
131 Float_t * fTmpCf1; //[fNCols] temp. coeffs for 2d summation
132 Float_t * fTmpCf0; //[fNRows] temp. coeffs for 1d summation
134 ClassDef(AliCheb3DCalc,1) // Class for interpolation of 3D->1 function by Chebyshev parametrization
138 class AliCheb3D: public TNamed
142 AliCheb3D(const char* inpFile); // read coefs from text file
143 AliCheb3D(FILE*); // read coefs from stream
145 #ifdef _INC_CREATION_ALICHEB3D_
146 AliCheb3D(const char* funName, Int_t DimOut, Float_t *bmin,Float_t *bmax, Int_t *npoints, Float_t prec=1E-6);
147 AliCheb3D(void (*ptr)(float*,float*), Int_t DimOut, Float_t *bmin,Float_t *bmax, Int_t *npoints, Float_t prec=1E-6);
150 ~AliCheb3D() {Clear();}
152 void Eval(Float_t *par,Float_t *res);
153 Float_t Eval(Float_t *par,int idim);
154 void Print(Option_t* opt="") const;
155 Bool_t IsInside(Float_t *par) const;
156 AliCheb3DCalc* GetChebCalc(int i) const {return (AliCheb3DCalc*)fChebCalc.UncheckedAt(i);}
157 Float_t GetBoundMin(int i) const {return fBMin[i];}
158 Float_t GetBoundMax(int i) const {return fBMax[i];}
159 Float_t GetPrecision() const {return fPrec;}
160 void ShiftBound(int id,float dif);
162 void LoadData(const char* inpFile);
163 void LoadData(FILE* stream);
165 #ifdef _INC_CREATION_ALICHEB3D_
166 void SaveData(const char* outfile,Bool_t append=kFALSE) const;
167 void SaveData(FILE* stream=stdout) const;
169 void SetUsrFunction(const char* name);
170 void SetUsrFunction(void (*ptr)(float*,float*));
171 void EvalUsrFunction(Float_t *x, Float_t *res);
172 TH1* TestRMS(int idim,int npoints = 1000,TH1* histo=0);
177 void Clear(Option_t* option = "");
178 void SetDimOut(int d);
179 void PrepareBoundaries(Float_t *bmin,Float_t *bmax);
181 #ifdef _INC_CREATION_ALICHEB3D_
182 void EvalUsrFunction();
183 void DefineGrid(Int_t* npoints);
184 Int_t ChebFit(); // fit all output dimensions
185 Int_t ChebFit(int dmOut);
186 Int_t CalcChebCoefs(Float_t *funval,int np, Float_t *outCoefs, Float_t prec=-1);
189 void Cyl2CartCyl(float *rphiz, float *b) const;
190 void Cart2Cyl(float *xyz,float *rphiz) const;
192 Float_t MapToInternal(Float_t x,Int_t d) const {return (x-fBOffset[d])*fBScale[d];} // map x to [-1:1]
193 Float_t MapToExternal(Float_t x,Int_t d) const {return x/fBScale[d]+fBOffset[d];} // map from [-1:1] to x
196 Int_t fDimOut; // dimension of the ouput array
197 Float_t fPrec; // requested precision
198 Float_t fBMin[3]; // min boundaries in each dimension
199 Float_t fBMax[3]; // max boundaries in each dimension
200 Float_t fBScale[3]; // scale for boundary mapping to [-1:1] interval
201 Float_t fBOffset[3]; // offset for boundary mapping to [-1:1] interval
202 TObjArray fChebCalc; // Chebyshev parameterization for each output dimension
204 Int_t fMaxCoefs; //! max possible number of coefs per parameterization
205 Int_t fNPoints[3]; //! number of used points in each dimension
206 Float_t fArgsTmp[3]; //! temporary vector for coefs caluclation
207 Float_t fBuff[6]; //! buffer for coordinate transformations
208 Float_t * fResTmp; //! temporary vector for results of user function caluclation
209 Float_t * fGrid; //! temporary buffer for Chebyshef roots grid
210 Int_t fGridOffs[3]; //! start of grid for each dimension
211 TString fUsrFunName; //! name of user macro containing the function of "void (*fcn)(float*,float*)" format
212 TMethodCall* fUsrMacro; //! Pointer to MethodCall for function from user macro
214 ClassDef(AliCheb3D,1) // Chebyshev parametrization for 3D->N function
217 // Pointer on user function (faster altrnative to TMethodCall)
218 #ifdef _INC_CREATION_ALICHEB3D_
219 void (*gUsrFunAliCheb3D) (float* ,float* );
222 //__________________________________________________________________________________________
223 #ifdef _INC_CREATION_ALICHEB3D_
224 inline void AliCheb3D::EvalUsrFunction()
226 // call user supplied function
227 if (gUsrFunAliCheb3D) gUsrFunAliCheb3D(fArgsTmp,fResTmp);
228 else fUsrMacro->Execute();
232 //__________________________________________________________________________________________
233 inline Bool_t AliCheb3D::IsInside(Float_t *par) const
235 // check if the point is inside of the fitted box
236 for (int i=3;i--;) if(par[i]<fBMin[i]||par[i]>fBMax[i]) return kFALSE;
240 //__________________________________________________________________________________________
241 inline Float_t AliCheb3DCalc::ChebEval1D(Float_t x, const Float_t * array, int ncf ) const
243 // evaluate 1D Chebyshev parameterization. x is the argument mapped to [-1:1] interval
248 for (int i=ncf;i--;) {
251 b0 = array[i] + x2*b1 -b2;
256 //__________________________________________________________________________________________
257 inline void AliCheb3D::Eval(Float_t *par, Float_t *res)
259 // evaluate Chebyshev parameterization for 3d->DimOut function
260 for (int i=3;i--;) fArgsTmp[i] = MapToInternal(par[i],i);
261 for (int i=fDimOut;i--;) res[i] = GetChebCalc(i)->Eval(fArgsTmp);
265 //__________________________________________________________________________________________
266 inline Float_t AliCheb3D::Eval(Float_t *par, int idim)
268 // evaluate Chebyshev parameterization for idim-th output dimension of 3d->DimOut function
269 for (int i=3;i--;) fArgsTmp[i] = MapToInternal(par[i],i);
270 return GetChebCalc(idim)->Eval(fArgsTmp);
274 //__________________________________________________________________________________________________
275 inline void AliCheb3D::Cyl2CartCyl(float *rphiz, float *b) const
277 // convert field in cylindrical coordinates to cartesian system, point is in cyl.system
278 float btr = TMath::Sqrt(b[0]*b[0]+b[1]*b[1]);
279 float ang = TMath::ATan2(b[1],b[0]) + rphiz[1];
280 b[0] = btr*TMath::Cos(ang);
281 b[1] = btr*TMath::Sin(ang);
285 //__________________________________________________________________________________________________
286 inline void AliCheb3D::Cart2Cyl(float *xyz,float *rphiz) const
288 // convert cartesian coordinate to cylindrical one
289 rphiz[0] = TMath::Sqrt(xyz[0]*xyz[0]+xyz[1]*xyz[1]);
290 rphiz[1] = TMath::ATan2(xyz[1],xyz[0]);