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FitAwmi.C File Reference
Tutorials » Spectrum tutorials

Detailed Description

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This macro fits the source spectrum using the AWMI algorithm from the "TSpectrumFit" class ("TSpectrum" class is used to find peaks).

To try this macro, in a ROOT (5 or 6) prompt, do:

root > .x FitAwmi.C

or:

root > .x FitAwmi.C++
root > FitAwmi(); // re-run with another random set of peaks
created -9.76 14.9603 3
created -9.28 4.98678 1
created -8.8 29.9207 6
created -8.32 49.8678 10
created -7.84 24.9339 5
created -7.36 14.9603 3
created -6.88 34.9074 7
created -6.4 14.9603 3
created -5.92 39.8942 8
created -5.44 34.9074 7
created -4.96 19.9471 4
created -4.48 49.8678 10
created -4 44.881 9
created -3.52 14.9603 3
created -3.04 39.8942 8
created -2.56 4.98678 1
created -2.08 29.9207 6
created -1.6 49.8678 10
created -1.12 44.881 9
created -0.64 9.97356 2
created -0.16 34.9074 7
created 0.32 19.9471 4
created 0.8 19.9471 4
created 1.28 34.9074 7
created 1.76 24.9339 5
created 2.24 14.9603 3
created 2.72 34.9074 7
created 3.2 34.9074 7
created 3.68 24.9339 5
created 4.16 34.9074 7
created 4.64 14.9603 3
created 5.12 44.881 9
created 5.6 39.8942 8
created 6.08 34.9074 7
created 6.56 19.9471 4
created 7.04 24.9339 5
created 7.52 24.9339 5
created 8 44.881 9
created 8.48 29.9207 6
created 8.96 29.9207 6
created 9.44 4.98678 1
the total number of created peaks = 41 with sigma = 0.08
the total number of found peaks = 41 with sigma = 0.0800011 (+-1.03292e-05)
fit chi^2 = 6.25767e-07
found -8.32 (+-8.70016e-05) 49.8676 (+-0.053504) 10.0001 (+-0.000354313)
found -4.48 (+-8.70708e-05) 49.8678 (+-0.0535095) 10.0001 (+-0.00035435)
found -1.6 (+-8.71816e-05) 49.8679 (+-0.0535177) 10.0002 (+-0.000354404)
found -4 (+-9.18119e-05) 44.881 (+-0.0507662) 9.00013 (+-0.000336183)
found -1.12 (+-9.17185e-05) 44.881 (+-0.0507604) 9.00012 (+-0.000336144)
found 5.12 (+-9.17293e-05) 44.8809 (+-0.0507603) 9.00011 (+-0.000336144)
found 8 (+-9.1772e-05) 44.8809 (+-0.0507627) 9.00011 (+-0.00033616)
found -5.92 (+-9.73195e-05) 39.8942 (+-0.0478587) 8.0001 (+-0.000316929)
found -3.04 (+-9.68029e-05) 39.8939 (+-0.0478289) 8.00004 (+-0.000316732)
found 5.6 (+-9.76942e-05) 39.8945 (+-0.0478814) 8.00016 (+-0.000317079)
found -6.88 (+-0.000103827) 34.9073 (+-0.0447564) 7.00006 (+-0.000296385)
found -5.44 (+-0.000104286) 34.9076 (+-0.0447808) 7.00012 (+-0.000296547)
found -0.16 (+-0.000103805) 34.9073 (+-0.0447555) 7.00006 (+-0.000296379)
found 1.28 (+-0.000104095) 34.9074 (+-0.0447703) 7.00009 (+-0.000296477)
found 2.72 (+-0.000104134) 34.9075 (+-0.0447728) 7.0001 (+-0.000296493)
found 3.2 (+-0.000104309) 34.9076 (+-0.0447818) 7.00012 (+-0.000296554)
found 4.16 (+-0.000104001) 34.9074 (+-0.0447655) 7.00008 (+-0.000296445)
found 6.08 (+-0.000104286) 34.9076 (+-0.0447808) 7.00012 (+-0.000296547)
found 8.48 (+-0.000113012) 29.921 (+-0.0414763) 6.00015 (+-0.000274664)
found 8.96 (+-0.000112213) 29.9206 (+-0.0414405) 6.00007 (+-0.000274427)
found -8.8 (+-0.000112466) 29.9208 (+-0.0414529) 6.00011 (+-0.000274509)
found -2.08 (+-0.000112466) 29.9208 (+-0.0414529) 6.00011 (+-0.000274509)
found -7.84 (+-0.000123738) 24.9342 (+-0.0378608) 5.00013 (+-0.000250721)
found 1.76 (+-0.000123524) 24.9341 (+-0.0378519) 5.0001 (+-0.000250662)
found 3.68 (+-0.00012394) 24.9343 (+-0.0378681) 5.00014 (+-0.000250769)
found 7.04 (+-0.000123472) 24.934 (+-0.0378495) 5.00009 (+-0.000250647)
found 7.52 (+-0.000123908) 24.9343 (+-0.037867) 5.00014 (+-0.000250762)
found -4.96 (+-0.000139126) 19.9477 (+-0.0338886) 4.00017 (+-0.000224417)
found 0.319999 (+-0.000138514) 19.9474 (+-0.0338686) 4.00011 (+-0.000224284)
found 6.56 (+-0.000138646) 19.9475 (+-0.0338728) 4.00012 (+-0.000224312)
found 0.800001 (+-0.000138514) 19.9474 (+-0.0338686) 4.00011 (+-0.000224284)
found -3.52 (+-0.000161181) 14.961 (+-0.0293619) 3.00017 (+-0.00019444)
found -7.36 (+-0.000160549) 14.9607 (+-0.0293459) 3.00012 (+-0.000194334)
found -6.4 (+-0.000160949) 14.9609 (+-0.029356) 3.00015 (+-0.000194401)
found 2.24 (+-0.000160549) 14.9607 (+-0.0293459) 3.00012 (+-0.000194334)
found 4.64 (+-0.00016106) 14.9609 (+-0.0293588) 3.00016 (+-0.00019442)
found -9.76 (+-0.000158574) 14.9602 (+-0.029297) 3.00001 (+-0.00019401)
found -0.640001 (+-0.00019824) 9.97424 (+-0.0239885) 2.00016 (+-0.000158856)
found -2.56 (+-0.000282604) 4.98743 (+-0.0169829) 1.00014 (+-0.000112464)
found 9.44 (+-0.000276329) 4.98707 (+-0.0169351) 1.00007 (+-0.000112147)
found -9.28 (+-0.00028066) 4.98717 (+-0.0169654) 1.00009 (+-0.000112348)
#include "TROOT.h"
#include "TMath.h"
#include "TRandom.h"
#include "TH1.h"
#include "TF1.h"
#include "TCanvas.h"
#include "TSpectrum.h"
#include "TSpectrumFit.h"
#include "TPolyMarker.h"
#include "TList.h"
#include <iostream>
TH1F *FitAwmi_Create_Spectrum(void) {
Int_t nbins = 1000;
Double_t xmin = -10., xmax = 10.;
delete gROOT->FindObject("h"); // prevent "memory leak"
TH1F *h = new TH1F("h", "simulated spectrum", nbins, xmin, xmax);
h->SetStats(kFALSE);
TF1 f("f", "TMath::Gaus(x, [0], [1], 1)", xmin, xmax);
// f.SetParNames("mean", "sigma");
gRandom->SetSeed(0); // make it really random
// create well separated peaks with exactly known means and areas
// note: TSpectrumFit assumes that all peaks have the same sigma
Double_t sigma = (xmax - xmin) / Double_t(nbins) * Int_t(gRandom->Uniform(2., 6.));
Int_t npeaks = 0;
while (xmax > (xmin + 6. * sigma)) {
npeaks++;
xmin += 3. * sigma; // "mean"
f.SetParameters(xmin, sigma);
Double_t area = 1. * Int_t(gRandom->Uniform(1., 11.));
h->Add(&f, area, ""); // "" ... or ... "I"
std::cout << "created "
<< xmin << " "
<< (area / sigma / TMath::Sqrt(TMath::TwoPi())) << " "
<< area << std::endl;
xmin += 3. * sigma;
}
std::cout << "the total number of created peaks = " << npeaks
<< " with sigma = " << sigma << std::endl;
return h;
}
void FitAwmi(void) {
TH1F *h = FitAwmi_Create_Spectrum();
TCanvas *cFit = ((TCanvas *)(gROOT->GetListOfCanvases()->FindObject("cFit")));
if (!cFit) cFit = new TCanvas("cFit", "cFit", 10, 10, 1000, 700);
else cFit->Clear();
h->Draw("L");
Int_t i, nfound, bin;
Int_t nbins = h->GetNbinsX();
Double_t *source = new Double_t[nbins];
Double_t *dest = new Double_t[nbins];
for (i = 0; i < nbins; i++) source[i] = h->GetBinContent(i + 1);
TSpectrum *s = new TSpectrum(); // note: default maxpositions = 100
// searching for candidate peaks positions
nfound = s->SearchHighRes(source, dest, nbins, 2., 2., kFALSE, 10000, kFALSE, 0);
// filling in the initial estimates of the input parameters
Bool_t *FixPos = new Bool_t[nfound];
Bool_t *FixAmp = new Bool_t[nfound];
for(i = 0; i < nfound; i++) FixAmp[i] = FixPos[i] = kFALSE;
Double_t *Pos, *Amp = new Double_t[nfound]; // ROOT 6
Pos = s->GetPositionX(); // 0 ... (nbins - 1)
for (i = 0; i < nfound; i++) {
bin = 1 + Int_t(Pos[i] + 0.5); // the "nearest" bin
Amp[i] = h->GetBinContent(bin);
}
TSpectrumFit *pfit = new TSpectrumFit(nfound);
pfit->SetFitParameters(0, (nbins - 1), 1000, 0.1, pfit->kFitOptimChiCounts,
pfit->kFitAlphaHalving, pfit->kFitPower2,
pfit->kFitTaylorOrderFirst);
pfit->SetPeakParameters(2., kFALSE, Pos, FixPos, Amp, FixAmp);
// pfit->SetBackgroundParameters(source[0], kFALSE, 0., kFALSE, 0., kFALSE);
pfit->FitAwmi(source);
Double_t *Positions = pfit->GetPositions();
Double_t *PositionsErrors = pfit->GetPositionsErrors();
Double_t *Amplitudes = pfit->GetAmplitudes();
Double_t *AmplitudesErrors = pfit->GetAmplitudesErrors();
Double_t *Areas = pfit->GetAreas();
Double_t *AreasErrors = pfit->GetAreasErrors();
delete gROOT->FindObject("d"); // prevent "memory leak"
TH1F *d = new TH1F(*h); d->SetNameTitle("d", ""); d->Reset("M");
for (i = 0; i < nbins; i++) d->SetBinContent(i + 1, source[i]);
Double_t x1 = d->GetBinCenter(1), dx = d->GetBinWidth(1);
Double_t sigma, sigmaErr;
pfit->GetSigma(sigma, sigmaErr);
// current TSpectrumFit needs a sqrt(2) correction factor for sigma
sigma /= TMath::Sqrt2(); sigmaErr /= TMath::Sqrt2();
// convert "bin numbers" into "x-axis values"
sigma *= dx; sigmaErr *= dx;
std::cout << "the total number of found peaks = " << nfound
<< " with sigma = " << sigma << " (+-" << sigmaErr << ")"
<< std::endl;
std::cout << "fit chi^2 = " << pfit->GetChi() << std::endl;
for (i = 0; i < nfound; i++) {
bin = 1 + Int_t(Positions[i] + 0.5); // the "nearest" bin
Pos[i] = d->GetBinCenter(bin);
Amp[i] = d->GetBinContent(bin);
// convert "bin numbers" into "x-axis values"
Positions[i] = x1 + Positions[i] * dx;
PositionsErrors[i] *= dx;
Areas[i] *= dx;
AreasErrors[i] *= dx;
std::cout << "found "
<< Positions[i] << " (+-" << PositionsErrors[i] << ") "
<< Amplitudes[i] << " (+-" << AmplitudesErrors[i] << ") "
<< Areas[i] << " (+-" << AreasErrors[i] << ")"
<< std::endl;
}
d->SetLineColor(kRed); d->SetLineWidth(1);
d->Draw("SAME L");
TPolyMarker *pm = ((TPolyMarker*)(h->GetListOfFunctions()->FindObject("TPolyMarker")));
if (pm) {
h->GetListOfFunctions()->Remove(pm);
delete pm;
}
pm = new TPolyMarker(nfound, Pos, Amp);
h->GetListOfFunctions()->Add(pm);
pm->SetMarkerStyle(23);
pm->SetMarkerColor(kRed);
pm->SetMarkerSize(1);
// cleanup
delete pfit;
delete [] Amp;
delete [] FixAmp;
delete [] FixPos;
delete s;
delete [] dest;
delete [] source;
return;
}
d
#define d(i)
Definition RSha256.hxx:102
f
#define f(i)
Definition RSha256.hxx:104
h
#define h(i)
Definition RSha256.hxx:106
Bool_t
bool Bool_t
Definition RtypesCore.h:63
Int_t
int Int_t
Definition RtypesCore.h:45
kFALSE
constexpr Bool_t kFALSE
Definition RtypesCore.h:101
Double_t
double Double_t
Definition RtypesCore.h:59
kRed
@ kRed
Definition Rtypes.h:66
dest
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t dest
Definition TGWin32VirtualXProxy.cxx:164
x1
Option_t Option_t TPoint TPoint const char x1
Definition TGWin32VirtualXProxy.cxx:70
i
Int_t i
Definition TGraphAsymmErrors.cxx:1306
xmin
float xmin
Definition THbookFile.cxx:95
xmax
float xmax
Definition THbookFile.cxx:95
gROOT
#define gROOT
Definition TROOT.h:414
gRandom
R__EXTERN TRandom * gRandom
Definition TRandom.h:62
TAttMarker::SetMarkerColor
virtual void SetMarkerColor(Color_t mcolor=1)
Set the marker color.
Definition TAttMarker.h:38
TAttMarker::SetMarkerStyle
virtual void SetMarkerStyle(Style_t mstyle=1)
Set the marker style.
Definition TAttMarker.h:40
TAttMarker::SetMarkerSize
virtual void SetMarkerSize(Size_t msize=1)
Set the marker size.
Definition TAttMarker.h:45
TCanvas
The Canvas class.
Definition TCanvas.h:23
TCanvas::Clear
void Clear(Option_t *option="") override
Remove all primitives from the canvas.
Definition TCanvas.cxx:734
TF1
1-Dim function class
Definition TF1.h:233
TH1F
1-D histogram with a float per channel (see TH1 documentation)
Definition TH1.h:621
TPolyMarker
A PolyMarker is defined by an array on N points in a 2-D space.
Definition TPolyMarker.h:31
TSpectrumFit
Advanced 1-dimensional spectra fitting functions.
Definition TSpectrumFit.h:18
TSpectrumFit::GetChi
Double_t GetChi() const
Definition TSpectrumFit.h:121
TSpectrumFit::SetPeakParameters
void SetPeakParameters(Double_t sigma, Bool_t fixSigma, const Double_t *positionInit, const Bool_t *fixPosition, const Double_t *ampInit, const Bool_t *fixAmp)
This function sets the following fitting parameters of peaks:
Definition TSpectrumFit.cxx:2658
TSpectrumFit::GetAmplitudesErrors
Double_t * GetAmplitudesErrors() const
Definition TSpectrumFit.h:117
TSpectrumFit::FitAwmi
void FitAwmi(Double_t *source)
This function fits the source spectrum.
Definition TSpectrumFit.cxx:822
TSpectrumFit::GetAreasErrors
Double_t * GetAreasErrors() const
Definition TSpectrumFit.h:119
TSpectrumFit::GetSigma
void GetSigma(Double_t &sigma, Double_t &sigmaErr)
This function gets the sigma parameter and its error.
Definition TSpectrumFit.cxx:2727
TSpectrumFit::GetAreas
Double_t * GetAreas() const
Definition TSpectrumFit.h:118
TSpectrumFit::GetAmplitudes
Double_t * GetAmplitudes() const
Definition TSpectrumFit.h:116
TSpectrumFit::SetFitParameters
void SetFitParameters(Int_t xmin, Int_t xmax, Int_t numberIterations, Double_t alpha, Int_t statisticType, Int_t alphaOptim, Int_t power, Int_t fitTaylor)
This function sets the following fitting parameters:
Definition TSpectrumFit.cxx:2610
TSpectrumFit::GetPositionsErrors
Double_t * GetPositionsErrors() const
Definition TSpectrumFit.h:123
TSpectrumFit::GetPositions
Double_t * GetPositions() const
Definition TSpectrumFit.h:122
TSpectrum
Advanced Spectra Processing.
Definition TSpectrum.h:18
TSpectrum::SearchHighRes
Int_t SearchHighRes(Double_t *source, Double_t *destVector, Int_t ssize, Double_t sigma, Double_t threshold, bool backgroundRemove, Int_t deconIterations, bool markov, Int_t averWindow)
One-dimensional high-resolution peak search function.
Definition TSpectrum.cxx:2129
TSpectrum::GetPositionX
Double_t * GetPositionX() const
Definition TSpectrum.h:58
sigma
const Double_t sigma
Definition h1analysisProxy.h:11
TMath::Sqrt2
constexpr Double_t Sqrt2()
Definition TMath.h:86
TMath::Sqrt
Double_t Sqrt(Double_t x)
Returns the square root of x.
Definition TMath.h:662
TMath::TwoPi
constexpr Double_t TwoPi()
Definition TMath.h:44
Author

Definition in file FitAwmi.C.