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FitAwmi.C File Reference
Tutorials » Legacy tutorials » Spectrum tutorials

Detailed Description

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 -9.82 46.5433 7
created -9.46 6.64904 1
created -9.1 19.9471 3
created -8.74 6.64904 1
created -8.38 53.1923 8
created -8.02 26.5962 4
created -7.66 53.1923 8
created -7.3 39.8942 6
created -6.94 19.9471 3
created -6.58 33.2452 5
created -6.22 26.5962 4
created -5.86 46.5433 7
created -5.5 19.9471 3
created -5.14 59.8413 9
created -4.78 39.8942 6
created -4.42 26.5962 4
created -4.06 53.1923 8
created -3.7 53.1923 8
created -3.34 39.8942 6
created -2.98 6.64904 1
created -2.62 66.4904 10
created -2.26 59.8413 9
created -1.9 19.9471 3
created -1.54 46.5433 7
created -1.18 26.5962 4
created -0.82 26.5962 4
created -0.46 66.4904 10
created -0.1 33.2452 5
created 0.26 59.8413 9
created 0.62 19.9471 3
created 0.98 26.5962 4
created 1.34 6.64904 1
created 1.7 39.8942 6
created 2.06 13.2981 2
created 2.42 26.5962 4
created 2.78 53.1923 8
created 3.14 53.1923 8
created 3.5 26.5962 4
created 3.86 59.8413 9
created 4.22 33.2452 5
created 4.58 26.5962 4
created 4.94 66.4904 10
created 5.3 6.64904 1
created 5.66 33.2452 5
created 6.02 13.2981 2
created 6.38 39.8942 6
created 6.74 33.2452 5
created 7.1 19.9471 3
created 7.46 39.8942 6
created 7.82 59.8413 9
created 8.18 19.9471 3
created 8.54 6.64904 1
created 8.9 19.9471 3
created 9.26 39.8942 6
created 9.62 6.64904 1
the total number of created peaks = 55 with sigma = 0.06
the total number of found peaks = 55 with sigma = 0.0600004 (+-5.65532e-06)
fit chi^2 = 4.14489e-07
found -2.62 (+-5.21678e-05) 66.4904 (+-0.0571532) 10.0001 (+-0.000288293)
found -0.46 (+-5.22225e-05) 66.4903 (+-0.0571582) 10.0001 (+-0.000288318)
found 4.94 (+-5.20263e-05) 66.4901 (+-0.0571341) 10 (+-0.000288197)
found -2.26 (+-5.51795e-05) 59.8415 (+-0.0542416) 9.00009 (+-0.000273606)
found -5.14 (+-5.50716e-05) 59.8413 (+-0.0542281) 9.00006 (+-0.000273538)
found 0.26 (+-5.50378e-05) 59.8413 (+-0.054224) 9.00005 (+-0.000273518)
found 3.86 (+-5.5083e-05) 59.8413 (+-0.0542292) 9.00006 (+-0.000273544)
found 7.82 (+-5.50716e-05) 59.8413 (+-0.0542281) 9.00006 (+-0.000273538)
found -3.7 (+-5.86519e-05) 53.1926 (+-0.0511523) 8.00009 (+-0.000258023)
found 3.14 (+-5.85709e-05) 53.1925 (+-0.0511437) 8.00008 (+-0.00025798)
found -8.38 (+-5.82287e-05) 53.1921 (+-0.0511084) 8.00003 (+-0.000257802)
found -7.66 (+-5.85062e-05) 53.1924 (+-0.0511366) 8.00007 (+-0.000257944)
found -4.06 (+-5.85709e-05) 53.1925 (+-0.0511437) 8.00008 (+-0.00025798)
found 2.78 (+-5.85709e-05) 53.1925 (+-0.0511437) 8.00008 (+-0.00025798)
found -9.82 (+-6.22639e-05) 46.543 (+-0.0478048) 7.00001 (+-0.000241137)
found -5.86 (+-6.24572e-05) 46.5432 (+-0.0478256) 7.00005 (+-0.000241243)
found -1.54 (+-6.24572e-05) 46.5432 (+-0.0478256) 7.00005 (+-0.000241243)
found -7.3 (+-6.77149e-05) 39.8944 (+-0.0442989) 6.00007 (+-0.000223453)
found -4.78 (+-6.78166e-05) 39.8945 (+-0.0443072) 6.00009 (+-0.000223495)
found -3.34 (+-6.75226e-05) 39.8944 (+-0.0442846) 6.00006 (+-0.000223381)
found 1.7 (+-6.7195e-05) 39.8941 (+-0.0442577) 6.00002 (+-0.000223245)
found 6.38 (+-6.75034e-05) 39.8943 (+-0.0442816) 6.00005 (+-0.000223366)
found 7.46 (+-6.77514e-05) 39.8945 (+-0.044302) 6.00008 (+-0.000223469)
found 9.26 (+-6.72741e-05) 39.8941 (+-0.0442638) 6.00003 (+-0.000223276)
found -0.1 (+-7.47093e-05) 33.2458 (+-0.0404765) 5.00013 (+-0.000204172)
found 4.22 (+-7.44044e-05) 33.2455 (+-0.0404549) 5.00009 (+-0.000204063)
found -6.58 (+-7.40668e-05) 33.2453 (+-0.0404311) 5.00005 (+-0.000203943)
found 5.66 (+-7.36743e-05) 33.2451 (+-0.0404057) 5.00002 (+-0.000203815)
found 6.74 (+-7.41878e-05) 33.2454 (+-0.0404396) 5.00006 (+-0.000203986)
found -8.02 (+-8.35726e-05) 26.5967 (+-0.036206) 4.00011 (+-0.000182631)
found -6.22 (+-8.33271e-05) 26.5965 (+-0.0361917) 4.00008 (+-0.000182559)
found -4.42 (+-8.34532e-05) 26.5966 (+-0.036199) 4.00009 (+-0.000182595)
found -1.18 (+-8.3248e-05) 26.5965 (+-0.0361873) 4.00007 (+-0.000182536)
found -0.819999 (+-8.34044e-05) 26.5966 (+-0.0361966) 4.00009 (+-0.000182584)
found 3.5 (+-8.3625e-05) 26.5967 (+-0.0362091) 4.00011 (+-0.000182646)
found 4.58 (+-8.34839e-05) 26.5966 (+-0.0362011) 4.0001 (+-0.000182606)
found 0.98 (+-8.25812e-05) 26.5961 (+-0.0361509) 4.00003 (+-0.000182353)
found 2.42 (+-8.30956e-05) 26.5964 (+-0.0361794) 4.00007 (+-0.000182497)
found -6.94 (+-9.64124e-05) 19.9475 (+-0.0313514) 3.00007 (+-0.000158143)
found -5.5 (+-9.68001e-05) 19.9477 (+-0.0313688) 3.00011 (+-0.000158231)
found -1.9 (+-9.68e-05) 19.9477 (+-0.0313688) 3.00011 (+-0.000158231)
found 0.619999 (+-9.65282e-05) 19.9476 (+-0.0313569) 3.00009 (+-0.000158171)
found 7.1 (+-9.64124e-05) 19.9475 (+-0.0313514) 3.00007 (+-0.000158143)
found 8.18 (+-9.60498e-05) 19.9474 (+-0.0313378) 3.00007 (+-0.000158075)
found -9.1 (+-9.51837e-05) 19.9471 (+-0.0313006) 3.00001 (+-0.000157887)
found 8.9 (+-9.58358e-05) 19.9473 (+-0.0313279) 3.00005 (+-0.000158025)
found 2.06 (+-0.000118457) 13.2984 (+-0.0256096) 2.00007 (+-0.00012918)
found 6.02 (+-0.000118601) 13.2985 (+-0.0256139) 2.00007 (+-0.000129202)
found 5.3 (+-0.000169946) 6.64967 (+-0.0181473) 1.0001 (+-9.15388e-05)
found -9.46 (+-0.00016888) 6.64944 (+-0.0181301) 1.00007 (+-9.14519e-05)
found -2.98 (+-0.000170173) 6.64971 (+-0.0181509) 1.00011 (+-9.15571e-05)
found -8.74 (+-0.000169059) 6.64949 (+-0.0181331) 1.00007 (+-9.14671e-05)
found 9.62 (+-0.000166078) 6.64931 (+-0.0180945) 1.00005 (+-9.12723e-05)
found 1.34 (+-0.00016899) 6.64944 (+-0.0181315) 1.00007 (+-9.14592e-05)
found 8.54 (+-0.000167905) 6.64926 (+-0.0181144) 1.00004 (+-9.1373e-05)
#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
Boolean (0=false, 1=true) (bool)
Definition RtypesCore.h:77
Int_t
int Int_t
Signed integer 4 bytes (int)
Definition RtypesCore.h:59
kFALSE
constexpr Bool_t kFALSE
Definition RtypesCore.h:108
Double_t
double Double_t
Double 8 bytes.
Definition RtypesCore.h:73
kRed
@ kRed
Definition Rtypes.h:67
TRangeDynCast
ROOT::Detail::TRangeCast< T, true > TRangeDynCast
TRangeDynCast is an adapter class that allows the typed iteration through a TCollection.
Definition TCollection.h:359
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
xmin
float xmin
Definition THbookFile.cxx:95
xmax
float xmax
Definition THbookFile.cxx:95
gROOT
#define gROOT
Definition TROOT.h:411
gRandom
R__EXTERN TRandom * gRandom
Definition TRandom.h:62
TCanvas
The Canvas class.
Definition TCanvas.h:23
TF1
1-Dim function class
Definition TF1.h:182
TH1F
1-D histogram with a float per channel (see TH1 documentation)
Definition TH1.h:878
TPolyMarker
A PolyMarker is defined by an array on N points in a 2-D space.
Definition TPolyMarker.h:31
TRandom::SetSeed
virtual void SetSeed(ULong_t seed=0)
Set the random generator seed.
Definition TRandom.cxx:614
TRandom::Uniform
virtual Double_t Uniform(Double_t x1=1)
Returns a uniform deviate on the interval (0, x1).
Definition TRandom.cxx:681
TSpectrumFit
Advanced 1-dimensional spectra fitting functions.
Definition TSpectrumFit.h:18
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:2118
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:89
TMath::Sqrt
Double_t Sqrt(Double_t x)
Returns the square root of x.
Definition TMath.h:673
TMath::TwoPi
constexpr Double_t TwoPi()
Definition TMath.h:47
Author

Definition in file FitAwmi.C.