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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 39.8942 6
created -9.46 46.5433 7
created -9.1 19.9471 3
created -8.74 13.2981 2
created -8.38 33.2452 5
created -8.02 6.64904 1
created -7.66 59.8413 9
created -7.3 33.2452 5
created -6.94 33.2452 5
created -6.58 19.9471 3
created -6.22 59.8413 9
created -5.86 53.1923 8
created -5.5 46.5433 7
created -5.14 26.5962 4
created -4.78 39.8942 6
created -4.42 6.64904 1
created -4.06 39.8942 6
created -3.7 59.8413 9
created -3.34 39.8942 6
created -2.98 19.9471 3
created -2.62 19.9471 3
created -2.26 46.5433 7
created -1.9 66.4904 10
created -1.54 26.5962 4
created -1.18 59.8413 9
created -0.82 66.4904 10
created -0.46 59.8413 9
created -0.1 59.8413 9
created 0.26 53.1923 8
created 0.62 66.4904 10
created 0.98 53.1923 8
created 1.34 66.4904 10
created 1.7 46.5433 7
created 2.06 13.2981 2
created 2.42 53.1923 8
created 2.78 13.2981 2
created 3.14 59.8413 9
created 3.5 59.8413 9
created 3.86 6.64904 1
created 4.22 59.8413 9
created 4.58 66.4904 10
created 4.94 66.4904 10
created 5.3 26.5962 4
created 5.66 33.2452 5
created 6.02 39.8942 6
created 6.38 6.64904 1
created 6.74 6.64904 1
created 7.1 33.2452 5
created 7.46 19.9471 3
created 7.82 66.4904 10
created 8.18 33.2452 5
created 8.54 53.1923 8
created 8.9 33.2452 5
created 9.26 26.5962 4
created 9.62 13.2981 2
the total number of created peaks = 55 with sigma = 0.06
the total number of found peaks = 55 with sigma = 0.0600004 (+-7.25014e-06)
fit chi^2 = 7.92493e-07
found -1.9 (+-7.22914e-05) 66.4904 (+-0.0790459) 10.0001 (+-0.000398724)
found -0.82 (+-7.2558e-05) 66.4907 (+-0.0790817) 10.0001 (+-0.000398905)
found 0.62 (+-7.24926e-05) 66.4906 (+-0.0790727) 10.0001 (+-0.000398859)
found 1.34 (+-7.24572e-05) 66.4906 (+-0.0790679) 10.0001 (+-0.000398835)
found 4.58 (+-7.25885e-05) 66.4908 (+-0.0790859) 10.0001 (+-0.000398926)
found 4.94 (+-7.23893e-05) 66.4905 (+-0.0790594) 10.0001 (+-0.000398792)
found 7.82 (+-7.21532e-05) 66.4903 (+-0.0790278) 10.0001 (+-0.000398633)
found -0.46 (+-7.65807e-05) 59.8418 (+-0.0750357) 9.00013 (+-0.000378496)
found -0.1 (+-7.65113e-05) 59.8417 (+-0.075027) 9.00011 (+-0.000378452)
found 3.5 (+-7.60818e-05) 59.8414 (+-0.0749781) 9.00007 (+-0.000378205)
found -7.66 (+-7.592e-05) 59.8412 (+-0.074958) 9.00004 (+-0.000378104)
found -6.22 (+-7.62304e-05) 59.8414 (+-0.0749934) 9.00007 (+-0.000378283)
found -3.7 (+-7.63131e-05) 59.8415 (+-0.0750026) 9.00008 (+-0.000378329)
found -1.18 (+-7.6362e-05) 59.8415 (+-0.0750093) 9.00009 (+-0.000378363)
found 3.14 (+-7.61883e-05) 59.8414 (+-0.0749893) 9.00007 (+-0.000378262)
found 4.22 (+-7.61146e-05) 59.8414 (+-0.0749823) 9.00007 (+-0.000378227)
found -5.86 (+-8.11872e-05) 53.1926 (+-0.0707401) 8.00011 (+-0.000356828)
found 0.26 (+-8.13072e-05) 53.1928 (+-0.0707535) 8.00013 (+-0.000356896)
found 0.98 (+-8.13444e-05) 53.1928 (+-0.0707577) 8.00013 (+-0.000356917)
found 2.42 (+-8.04789e-05) 53.1921 (+-0.0706652) 8.00003 (+-0.00035645)
found 8.54 (+-8.09061e-05) 53.1924 (+-0.0707093) 8.00007 (+-0.000356673)
found -5.5 (+-8.66657e-05) 46.5435 (+-0.0661593) 7.00008 (+-0.000333722)
found 1.7 (+-8.65751e-05) 46.5435 (+-0.0661522) 7.00008 (+-0.000333686)
found -9.46 (+-8.64868e-05) 46.5433 (+-0.0661423) 7.00006 (+-0.000333636)
found -2.26 (+-8.66725e-05) 46.5435 (+-0.0661608) 7.00009 (+-0.000333729)
found -3.34 (+-9.36827e-05) 39.8945 (+-0.0612583) 6.00008 (+-0.000309)
found -9.82 (+-9.35762e-05) 39.8943 (+-0.0612439) 6.00005 (+-0.000308927)
found -4.78 (+-9.3111e-05) 39.8942 (+-0.0612125) 6.00003 (+-0.000308769)
found -4.06 (+-9.34164e-05) 39.8944 (+-0.0612385) 6.00007 (+-0.0003089)
found 6.02 (+-9.31863e-05) 39.8942 (+-0.0612187) 6.00004 (+-0.0003088)
found -7.3 (+-0.000102972) 33.2456 (+-0.0559448) 5.00009 (+-0.000282198)
found 8.18 (+-0.000103244) 33.2458 (+-0.0559642) 5.00012 (+-0.000282295)
found 8.9 (+-0.000102823) 33.2455 (+-0.0559343) 5.00008 (+-0.000282144)
found -8.38 (+-0.000101873) 33.2451 (+-0.0558706) 5.00002 (+-0.000281823)
found -6.94 (+-0.000102504) 33.2453 (+-0.0559119) 5.00005 (+-0.000282032)
found 5.66 (+-0.000102688) 33.2454 (+-0.0559245) 5.00007 (+-0.000282095)
found 7.1 (+-0.000102001) 33.2451 (+-0.055879) 5.00003 (+-0.000281866)
found -5.14 (+-0.000115316) 26.5965 (+-0.0500492) 4.00009 (+-0.000252459)
found -1.54 (+-0.000115772) 26.5968 (+-0.0500762) 4.00013 (+-0.000252595)
found 5.3 (+-0.000115437) 26.5966 (+-0.0500567) 4.0001 (+-0.000252497)
found 9.26 (+-0.000114643) 26.5963 (+-0.0500117) 4.00005 (+-0.00025227)
found -9.1 (+-0.000132911) 19.9474 (+-0.0433344) 3.00006 (+-0.000218588)
found -6.58 (+-0.000133615) 19.9476 (+-0.0433645) 3.00009 (+-0.00021874)
found -2.98 (+-0.000133008) 19.9474 (+-0.0433378) 3.00006 (+-0.000218605)
found 7.46 (+-0.0001337) 19.9476 (+-0.0433685) 3.0001 (+-0.00021876)
found -2.62 (+-0.000133117) 19.9474 (+-0.0433428) 3.00007 (+-0.00021863)
found 2.06 (+-0.00016462) 13.2987 (+-0.0354366) 2.0001 (+-0.00017875)
found 2.78 (+-0.000164891) 13.2987 (+-0.0354451) 2.00011 (+-0.000178793)
found -8.74 (+-0.000163389) 13.2983 (+-0.0353993) 2.00005 (+-0.000178562)
found 9.62 (+-0.0001613) 13.2983 (+-0.0353484) 2.00004 (+-0.000178305)
found 3.86 (+-0.000235856) 6.6498 (+-0.025107) 1.00012 (+-0.000126645)
found -8.02 (+-0.000234779) 6.64962 (+-0.0250894) 1.00009 (+-0.000126556)
found -4.42 (+-0.000234336) 6.64953 (+-0.0250818) 1.00008 (+-0.000126518)
found 6.38 (+-0.000231953) 6.64931 (+-0.0250461) 1.00005 (+-0.000126338)
found 6.74 (+-0.000231652) 6.64926 (+-0.0250411) 1.00004 (+-0.000126313)
#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.