1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 // Author: ruben.shahoyan@cern.ch 09/09/2006
20 ////////////////////////////////////////////////////////////////////////////////
22 // AliCheb3D produces the interpolation of the user 3D->NDimOut arbitrary //
23 // function supplied in "void (*fcn)(float* inp,float* out)" format //
24 // either in a separate macro file or as a function pointer. //
25 // Only coefficients needed to guarantee the requested precision are kept. //
27 // The user-callable methods are: //
28 // To create the interpolation use: //
29 // AliCheb3D(const char* funName, // name of the file with user function //
31 // AliCheb3D(void (*ptr)(float*,float*),// pointer on the user function //
32 // Int_t DimOut, // dimensionality of the function's output //
33 // Float_t *bmin, // lower 3D bounds of interpolation domain //
34 // Float_t *bmax, // upper 3D bounds of interpolation domain //
35 // Int_t *npoints, // number of points in each of 3 input //
36 // // dimension, defining the interpolation grid //
37 // Float_t prec=1E-6); // requested max.absolute difference between //
38 // // the interpolation and any point on grid //
40 // To test obtained parameterization use the method //
41 // TH1* TestRMS(int idim,int npoints = 1000,TH1* histo=0); //
42 // it will compare the user output of the user function and interpolation //
43 // for idim-th output dimension and fill the difference in the supplied //
44 // histogram. If no histogram is supplied, it will be created. //
46 // To save the interpolation data: //
47 // SaveData(const char* filename, Bool_t append ) //
48 // write text file with data. If append is kTRUE and the output file already //
49 // exists, data will be added in the end of the file. //
50 // Alternatively, SaveData(FILE* stream) will write the data to //
51 // already existing stream. //
53 // To read back already stored interpolation use either the constructor //
54 // AliCheb3D(const char* inpFile); //
55 // or the default constructor AliCheb3D() followed by //
56 // AliCheb3D::LoadData(const char* inpFile); //
58 // To compute the interpolation use Eval(float* par,float *res) method, with //
59 // par being 3D vector of arguments (inside the validity region) and res is //
60 // the array of DimOut elements for the output. //
62 // If only one component (say, idim-th) of the output is needed, use faster //
63 // Float_t Eval(Float_t *par,int idim) method. //
65 // void Print(option="") will print the name, the ranges of validity and //
66 // the absolute precision of the parameterization. Option "l" will also print //
67 // the information about the number of coefficients for each output //
70 // NOTE: during the evaluation no check is done for parameter vector being //
71 // outside the interpolation region. If there is such a risk, use //
72 // Bool_t IsInside(float *par) method. Chebyshev parameterization is not //
73 // good for extrapolation! //
75 // For the properties of Chebyshev parameterization see: //
76 // H.Wind, CERN EP Internal Report, 81-12/Rev. //
78 ////////////////////////////////////////////////////////////////////////////////
84 #include "AliCheb3D.h"
91 AliCheb3D::AliCheb3D():
102 // Default constructor
106 AliCheb3D::AliCheb3D(const char* inputFile):
117 // Default constructor
124 AliCheb3D::AliCheb3D(FILE* stream):
135 // Default constructor
140 AliCheb3D::AliCheb3D(const AliCheb3D& src) :
142 fDimOut(src.fDimOut),
145 fMaxCoefs(src.fMaxCoefs),
148 fUsrFunName(src.fUsrFunName),
152 // read coefs from text file
154 fBMin[i] = src.fBMin[i];
155 fBMax[i] = src.fBMax[i];
156 fBScale[i] = src.fBScale[i];
157 fBOffset[i] = src.fBOffset[i];
158 fNPoints[i] = src.fNPoints[i];
160 for (int i=0;i<fDimOut;i++) {
161 AliCheb3DCalc* cbc = src.GetChebCalc(i);
162 if (cbc) fChebCalc.AddAtAndExpand(new AliCheb3DCalc(*cbc),i);
166 AliCheb3D& AliCheb3D::operator=(const AliCheb3D& rhs)
168 // Assignment operator
171 fDimOut = rhs.fDimOut;
173 fMaxCoefs = rhs.fMaxCoefs;
174 fUsrFunName = rhs.fUsrFunName;
177 fBMin[i] = rhs.fBMin[i];
178 fBMax[i] = rhs.fBMax[i];
179 fBScale[i] = rhs.fBScale[i];
180 fBOffset[i] = rhs.fBOffset[i];
181 fNPoints[i] = rhs.fNPoints[i];
183 for (int i=0;i<fDimOut;i++) {
184 AliCheb3DCalc* cbc = rhs.GetChebCalc(i);
185 if (cbc) fChebCalc.AddAtAndExpand(new AliCheb3DCalc(*cbc),i);
193 //__________________________________________________________________________________________
194 #ifdef _INC_CREATION_ALICHEB3D_
195 AliCheb3D::AliCheb3D(const char* funName, int DimOut, Float_t *bmin,Float_t *bmax, Int_t *npoints, Float_t prec) : TNamed(funName,funName)
197 // Construct the parameterization for the function
198 // funName : name of the file containing the function: void funName(Float_t * inp,Float_t * out)
199 // DimOut : dimension of the vector computed by the user function
200 // bmin : array of 3 elements with the lower boundaries of the region where the function is defined
201 // bmax : array of 3 elements with the upper boundaries of the region where the function is defined
202 // npoints : array of 3 elements with the number of points to compute in each of 3 dimension
203 // prec : max allowed absolute difference between the user function and computed parameterization on the requested grid
206 fPrec = TMath::Max(1.E-12f,prec);
207 if (DimOut<1) {Error("AliCheb3D","Requested output dimension is %d\nStop\n",fDimOut); exit(1);}
209 PrepareBoundaries(bmin,bmax);
211 SetUsrFunction(funName);
217 //__________________________________________________________________________________________
218 #ifdef _INC_CREATION_ALICHEB3D_
219 AliCheb3D::AliCheb3D(void (*ptr)(float*,float*), int DimOut, Float_t *bmin,Float_t *bmax, Int_t *npoints, Float_t prec) : TNamed("AliCheb3D","AliCheb3D")
221 // Construct the parameterization for the function
222 // ptr : pointer on the function: void fun(Float_t * inp,Float_t * out)
223 // DimOut : dimension of the vector computed by the user function
224 // bmin : array of 3 elements with the lower boundaries of the region where the function is defined
225 // bmax : array of 3 elements with the upper boundaries of the region where the function is defined
226 // npoints : array of 3 elements with the number of points to compute in each of 3 dimension
227 // prec : max allowed absolute difference between the user function and computed parameterization on the requested grid
230 fPrec = TMath::Max(1.E-12f,prec);
231 if (DimOut<1) {Error("AliCheb3D","Requested output dimension is %d\nStop\n",fDimOut); exit(1);}
233 PrepareBoundaries(bmin,bmax);
242 //__________________________________________________________________________________________
243 void AliCheb3D::Clear(Option_t*)
246 if (fResTmp) { delete[] fResTmp; fResTmp = 0; }
247 if (fGrid) { delete[] fGrid; fGrid = 0; }
248 if (fUsrMacro) { delete fUsrMacro; fUsrMacro = 0;}
253 //__________________________________________________________________________________________
254 void AliCheb3D::Print(Option_t* opt) const
256 // Print Chebyshev parameterisation data
257 printf("%s: Chebyshev parameterization for 3D->%dD function. Precision: %e\n",GetName(),fDimOut,fPrec);
258 printf("Region of validity: [%+.5e:%+.5e] [%+.5e:%+.5e] [%+.5e:%+.5e]\n",fBMin[0],fBMax[0],fBMin[1],fBMax[1],fBMin[2],fBMax[2]);
259 TString opts = opt; opts.ToLower();
260 if (opts.Contains("l")) for (int i=0;i<fDimOut;i++) {printf("Output dimension %d:\n",i+1); GetChebCalc(i)->Print();}
264 //__________________________________________________________________________________________
265 void AliCheb3D::Init0()
268 for (int i=3;i--;) fBMin[i] = fBMax[i] = fBScale[i] = fBOffset[i] = 0;
274 #ifdef _INC_CREATION_ALICHEB3D_
275 gUsrFunAliCheb3D = 0;
279 //__________________________________________________________________________________________
280 void AliCheb3D::PrepareBoundaries(Float_t *bmin,Float_t *bmax)
282 // Set and check boundaries defined by user, prepare coefficients for their conversion to [-1:1] interval
287 fBScale[i] = bmax[i]-bmin[i];
289 Error("PrepareBoundaries","Boundaries for %d-th dimension are not increasing: %+.4e %+.4e\nStop\n",i,fBMin[i],fBMax[i]);
292 fBOffset[i] = bmin[i] + fBScale[i]/2.0;
293 fBScale[i] = 2./fBScale[i];
298 //__________________________________________________________________________________________
299 #ifdef _INC_CREATION_ALICHEB3D_
300 void AliCheb3D::SetUsrFunction(const char* name)
302 // load user macro with function definition and compile it
303 gUsrFunAliCheb3D = 0;
305 gSystem->ExpandPathName(fUsrFunName);
306 if (fUsrMacro) delete fUsrMacro;
307 TString tmpst = fUsrFunName;
308 tmpst += "+"; // prepare filename to compile
309 if (gROOT->LoadMacro(tmpst.Data())) {Error("SetUsrFunction","Failed to load user function from %s\nStop\n",name); exit(1);}
310 fUsrMacro = new TMethodCall();
311 tmpst = tmpst.Data() + tmpst.Last('/')+1; //Strip away any path preceding the macro file name
312 int dot = tmpst.Last('.');
313 if (dot>0) tmpst.Resize(dot);
314 fUsrMacro->InitWithPrototype(tmpst.Data(),"Float_t *,Float_t *");
316 args[0] = (long)fArgsTmp;
317 args[1] = (long)fResTmp;
318 fUsrMacro->SetParamPtrs(args);
323 //__________________________________________________________________________________________
324 #ifdef _INC_CREATION_ALICHEB3D_
325 void AliCheb3D::SetUsrFunction(void (*ptr)(float*,float*))
327 if (fUsrMacro) delete fUsrMacro;
330 gUsrFunAliCheb3D = ptr;
334 //__________________________________________________________________________________________
335 #ifdef _INC_CREATION_ALICHEB3D_
336 void AliCheb3D::EvalUsrFunction(Float_t *x, Float_t *res) {
337 for (int i=3;i--;) fArgsTmp[i] = x[i];
338 if (gUsrFunAliCheb3D) gUsrFunAliCheb3D(fArgsTmp,fResTmp);
339 else fUsrMacro->Execute();
340 for (int i=fDimOut;i--;) res[i] = fResTmp[i];
344 //__________________________________________________________________________________________
345 #ifdef _INC_CREATION_ALICHEB3D_
346 Int_t AliCheb3D::CalcChebCoefs(Float_t *funval,int np, Float_t *outCoefs, Float_t prec)
348 // Calculate Chebyshev coeffs using precomputed function values at np roots.
349 // If prec>0, estimate the highest coeff number providing the needed precision
351 double sm; // do summations in double to minimize the roundoff error
352 for (int ic=0;ic<np;ic++) { // compute coeffs
354 for (int ir=0;ir<np;ir++) {
355 float rt = TMath::Cos( ic*(ir+0.5)*TMath::Pi()/np);
358 outCoefs[ic] = Float_t( sm * ((ic==0) ? 1./np : 2./np) );
361 if (prec<=0) return np;
365 for (cfMax=np;cfMax--;) {
366 sm += TMath::Abs(outCoefs[cfMax]);
369 if (++cfMax==0) cfMax=1;
375 //__________________________________________________________________________________________
376 #ifdef _INC_CREATION_ALICHEB3D_
377 void AliCheb3D::DefineGrid(Int_t* npoints)
379 // prepare the grid of Chebyshev roots in each dimension
380 const int kMinPoints = 1;
383 for (int id=3;id--;) {
384 fNPoints[id] = npoints[id];
385 if (fNPoints[id]<kMinPoints) {
386 Error("DefineGrid","at %d-th dimension %d point is requested, at least %d is needed\nStop\n",fNPoints[id],kMinPoints);
389 ntot += fNPoints[id];
390 fMaxCoefs *= fNPoints[id];
392 fGrid = new Float_t [ntot];
395 for (int id=3;id--;) {
396 int np = fNPoints[id];
397 fGridOffs[id] = curp;
398 for (int ip=0;ip<np;ip++) {
399 Float_t x = TMath::Cos( TMath::Pi()*(ip+0.5)/np );
400 fGrid[curp++] = MapToExternal(x,id);
407 //__________________________________________________________________________________________
408 #ifdef _INC_CREATION_ALICHEB3D_
409 Int_t AliCheb3D::ChebFit()
411 // prepare parameterization for all output dimensions
413 for (int i=fDimOut;i--;) ir+=ChebFit(i);
418 //__________________________________________________________________________________________
419 #ifdef _INC_CREATION_ALICHEB3D_
420 Int_t AliCheb3D::ChebFit(int dmOut)
422 // prepare paramaterization of 3D function for dmOut-th dimension
424 for (int i=0;i<3;i++) if (maxDim<fNPoints[i]) maxDim = fNPoints[i];
425 Float_t *fvals = new Float_t [ fNPoints[0] ];
426 Float_t *tmpCoef3D = new Float_t [ fNPoints[0]*fNPoints[1]*fNPoints[2] ];
427 Float_t *tmpCoef2D = new Float_t [ fNPoints[0]*fNPoints[1] ];
428 Float_t *tmpCoef1D = new Float_t [ maxDim ];
430 Float_t RTiny = fPrec/Float_t(maxDim); // neglect coefficient below this threshold
432 // 1D Cheb.fit for 0-th dimension at current steps of remaining dimensions
435 AliCheb3DCalc* cheb = GetChebCalc(dmOut);
437 for (int id2=fNPoints[2];id2--;) {
438 fArgsTmp[2] = fGrid[ fGridOffs[2]+id2 ];
440 for (int id1=fNPoints[1];id1--;) {
441 fArgsTmp[1] = fGrid[ fGridOffs[1]+id1 ];
443 for (int id0=fNPoints[0];id0--;) {
444 fArgsTmp[0] = fGrid[ fGridOffs[0]+id0 ];
445 EvalUsrFunction(); // compute function values at Chebyshev roots of 0-th dimension
446 fvals[id0] = fResTmp[dmOut];
448 int nc = CalcChebCoefs(fvals,fNPoints[0], tmpCoef1D, fPrec);
449 for (int id0=fNPoints[0];id0--;) tmpCoef2D[id1 + id0*fNPoints[1]] = tmpCoef1D[id0];
450 if (ncmax<nc) ncmax = nc; // max coefs to be kept in dim0 to guarantee needed precision
453 // once each 1d slice of given 2d slice is parametrized, parametrize the Cheb.coeffs
454 for (int id0=fNPoints[0];id0--;) {
455 CalcChebCoefs( tmpCoef2D+id0*fNPoints[1], fNPoints[1], tmpCoef1D, -1);
456 for (int id1=fNPoints[1];id1--;) tmpCoef3D[id2 + fNPoints[2]*(id1+id0*fNPoints[1])] = tmpCoef1D[id1];
460 // now fit the last dimensions Cheb.coefs
461 for (int id0=fNPoints[0];id0--;) {
462 for (int id1=fNPoints[1];id1--;) {
463 CalcChebCoefs( tmpCoef3D+ fNPoints[2]*(id1+id0*fNPoints[1]), fNPoints[2], tmpCoef1D, -1);
464 for (int id2=fNPoints[2];id2--;) tmpCoef3D[id2+ fNPoints[2]*(id1+id0*fNPoints[1])] = tmpCoef1D[id2]; // store on place
468 // now find 2D surface which separates significant coefficients of 3D matrix from nonsignificant ones (up to fPrec)
469 int *tmpCoefSurf = new Int_t[ fNPoints[0]*fNPoints[1] ];
470 for (int id0=fNPoints[0];id0--;) for (int id1=fNPoints[1];id1--;) tmpCoefSurf[id1+id0*fNPoints[1]]=0;
472 for (int id0=fNPoints[0];id0--;) {
473 for (int id1=fNPoints[1];id1--;) {
474 for (int id2=fNPoints[2];id2--;) {
475 int id = id2 + fNPoints[2]*(id1+id0*fNPoints[1]);
476 Float_t cfa = TMath::Abs(tmpCoef3D[id]);
477 if (cfa < RTiny) {tmpCoef3D[id] = 0; continue;} // neglect coeefs below the threshold
480 if (resid<fPrec) continue; // this coeff is negligible
481 // otherwise go back 1 step
483 tmpCoefSurf[id1+id0*fNPoints[1]] = id2+1; // how many coefs to keep
489 printf("\n\nCoeffs\n");
491 for (int id0=0;id0<fNPoints[0];id0++) {
492 for (int id1=0;id1<fNPoints[1];id1++) {
493 for (int id2=0;id2<fNPoints[2];id2++) {
494 printf("%2d%2d%2d %+.4e |",id0,id1,id2,tmpCoef3D[cnt++]);
501 // see if there are rows to reject, find max.significant column at each row
502 int NRows = fNPoints[0];
503 int *tmpCols = new int[NRows];
504 for (int id0=fNPoints[0];id0--;) {
505 int id1 = fNPoints[1];
506 while (id1>0 && tmpCoefSurf[(id1-1)+id0*fNPoints[1]]==0) id1--;
509 // find max significant row
510 for (int id0=NRows;id0--;) {if (tmpCols[id0]>0) break; NRows--;}
511 // find max significant column and fill the permanent storage for the max sigificant column of each row
512 cheb->InitRows(NRows); // create needed arrays;
513 int *NColsAtRow = cheb->GetNColsAtRow();
514 int *ColAtRowBg = cheb->GetColAtRowBg();
516 int NElemBound2D = 0;
517 for (int id0=0;id0<NRows;id0++) {
518 NColsAtRow[id0] = tmpCols[id0]; // number of columns to store for this row
519 ColAtRowBg[id0] = NElemBound2D; // begining of this row in 2D boundary surface
520 NElemBound2D += tmpCols[id0];
521 if (NCols<NColsAtRow[id0]) NCols = NColsAtRow[id0];
523 cheb->InitCols(NCols);
526 // create the 2D matrix defining the boundary of significance for 3D coeffs.matrix
527 // and count the number of siginifacnt coefficients
529 cheb->InitElemBound2D(NElemBound2D);
530 int *CoefBound2D0 = cheb->GetCoefBound2D0();
531 int *CoefBound2D1 = cheb->GetCoefBound2D1();
532 fMaxCoefs = 0; // redefine number of coeffs
533 for (int id0=0;id0<NRows;id0++) {
534 int nCLoc = NColsAtRow[id0];
535 int col0 = ColAtRowBg[id0];
536 for (int id1=0;id1<nCLoc;id1++) {
537 CoefBound2D0[col0 + id1] = tmpCoefSurf[id1+id0*fNPoints[1]]; // number of coefs to store for 3-d dimension
538 CoefBound2D1[col0 + id1] = fMaxCoefs;
539 fMaxCoefs += CoefBound2D0[col0 + id1];
543 // create final compressed 3D matrix for significant coeffs
544 cheb->InitCoefs(fMaxCoefs);
545 Float_t *Coefs = cheb->GetCoefs();
547 for (int id0=0;id0<NRows;id0++) {
548 int ncLoc = NColsAtRow[id0];
549 int col0 = ColAtRowBg[id0];
550 for (int id1=0;id1<ncLoc;id1++) {
551 int ncf2 = CoefBound2D0[col0 + id1];
552 for (int id2=0;id2<ncf2;id2++) {
553 Coefs[count++] = tmpCoef3D[id2 + fNPoints[2]*(id1+id0*fNPoints[1])];
558 printf("\n\nNewSurf\n");
559 for (int id0=0;id0<fNPoints[0];id0++) {
560 for (int id1=0;id1<fNPoints[1];id1++) {
561 printf("(%2d %2d) %2d |",id0,id1,tmpCoefSurf[id1+id0*fNPoints[1]]);
567 delete[] tmpCoefSurf;
577 //_______________________________________________
578 #ifdef _INC_CREATION_ALICHEB3D_
579 void AliCheb3D::SaveData(const char* outfile,Bool_t append) const
581 // writes coefficients data to output text file, optionallt appending on the end of existing file
582 TString strf = outfile;
583 gSystem->ExpandPathName(strf);
584 FILE* stream = fopen(strf,append ? "a":"w");
591 //_______________________________________________
592 #ifdef _INC_CREATION_ALICHEB3D_
593 void AliCheb3D::SaveData(FILE* stream) const
595 // writes coefficients data to existing output stream
597 fprintf(stream,"\n# These are automatically generated data for the Chebyshev interpolation of 3D->%dD function\n",fDimOut);
598 fprintf(stream,"#\nSTART %s\n",GetName());
599 fprintf(stream,"# Dimensionality of the output\n%d\n",fDimOut);
600 fprintf(stream,"# Interpolation abs. precision\n%+.8e\n",fPrec);
602 fprintf(stream,"# Lower boundaries of interpolation region\n");
603 for (int i=0;i<3;i++) fprintf(stream,"%+.8e\n",fBMin[i]);
604 fprintf(stream,"# Upper boundaries of interpolation region\n");
605 for (int i=0;i<3;i++) fprintf(stream,"%+.8e\n",fBMax[i]);
606 fprintf(stream,"# Parameterization for each output dimension follows:\n",GetName());
608 for (int i=0;i<fDimOut;i++) GetChebCalc(i)->SaveData(stream);
609 fprintf(stream,"#\nEND %s\n#\n",GetName());
614 //_______________________________________________
615 void AliCheb3D::LoadData(const char* inpFile)
617 // Load data from input file
618 TString strf = inpFile;
619 gSystem->ExpandPathName(strf);
620 FILE* stream = fopen(strf.Data(),"r");
626 //_______________________________________________
627 void AliCheb3D::LoadData(FILE* stream)
629 // Load data from input stream stream
630 if (!stream) {Error("LoadData","No stream provided.\nStop"); exit(1);}
633 AliCheb3DCalc::ReadLine(buffs,stream);
634 if (!buffs.BeginsWith("START")) {Error("LoadData","Expected: \"START <fit_name>\", found \"%s\"\nStop\n",buffs.Data());exit(1);}
635 SetName(buffs.Data()+buffs.First(' ')+1);
637 AliCheb3DCalc::ReadLine(buffs,stream); // N output dimensions
638 fDimOut = buffs.Atoi();
639 if (fDimOut<1) {Error("LoadData","Expected: '<number_of_output_dimensions>', found \"%s\"\nStop\n",buffs.Data());exit(1);}
643 AliCheb3DCalc::ReadLine(buffs,stream); // Interpolation abs. precision
644 fPrec = buffs.Atof();
645 if (fPrec<=0) {Error("LoadData","Expected: '<abs.precision>', found \"%s\"\nStop\n",buffs.Data());exit(1);}
647 for (int i=0;i<3;i++) { // Lower boundaries of interpolation region
648 AliCheb3DCalc::ReadLine(buffs,stream);
649 fBMin[i] = buffs.Atof();
651 for (int i=0;i<3;i++) { // Upper boundaries of interpolation region
652 AliCheb3DCalc::ReadLine(buffs,stream);
653 fBMax[i] = buffs.Atof();
655 PrepareBoundaries(fBMin,fBMax);
657 // data for each output dimension
658 for (int i=0;i<fDimOut;i++) GetChebCalc(i)->LoadData(stream);
660 // check end_of_data record
661 AliCheb3DCalc::ReadLine(buffs,stream);
662 if (!buffs.BeginsWith("END") || !buffs.Contains(GetName())) {
663 Error("LoadData","Expected \"END %s\", found \"%s\".\nStop\n",GetName(),buffs.Data());
669 //_______________________________________________
670 void AliCheb3D::SetDimOut(int d)
672 // Set the dimension of the output array
674 if (fResTmp) delete fResTmp;
675 fResTmp = new Float_t[fDimOut]; // RRR
677 for (int i=0;i<d;i++) fChebCalc.AddAtAndExpand(new AliCheb3DCalc(),i);
680 //_______________________________________________
681 void AliCheb3D::ShiftBound(int id,float dif)
683 //Shift the boundary of dimension id
684 if (id<0||id>2) {printf("Maximum 3 dimensions are supported\n"); return;}
690 //_______________________________________________
691 #ifdef _INC_CREATION_ALICHEB3D_
692 TH1* AliCheb3D::TestRMS(int idim,int npoints,TH1* histo)
694 // fills the difference between the original function and parameterization (for idim-th component of the output)
695 // to supplied histogram. Calculations are done in npoints random points.
696 // If the hostgram was not supplied, it will be created. It is up to the user to delete it!
698 printf("No user function is set\n");
701 if (!histo) histo = new TH1D(GetName(),"Control: Function - Parametrization",100,-2*fPrec,2*fPrec);
702 for (int ip=npoints;ip--;) {
703 gRandom->RndmArray(3,(Float_t *)fArgsTmp);
704 for (int i=3;i--;) fArgsTmp[i] = fBMin[i] + fArgsTmp[i]*(fBMax[i]-fBMin[i]);
706 Float_t valFun = fResTmp[idim];
707 Eval(fArgsTmp,fResTmp);
708 Float_t valPar = fResTmp[idim];
709 histo->Fill(valFun - valPar);