Skip to content

[hist] Add option I to TH1::Chisquare for bin integral chi2 #21951

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
JasMehta08 wants to merge 1 commit into
base: master
Choose a base branch
from
+9 −6
Open

[hist] Add option I to TH1::Chisquare for bin integral chi2 #21951

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion hist/hist/inc/HFitInterface.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -169,7 +169,7 @@ namespace ROOT {
/**
compute the chi2 value for an histogram given a function (see TH1::Chisquare for the documentation)
*/
double Chisquare(const TH1 & h1, TF1 & f1, bool useRange, EChisquareType type);
double Chisquare(const TH1 & h1, TF1 & f1, bool useRange, EChisquareType type, bool useIntegral = false);

/**
compute the chi2 value for a graph given a function (see TGraph::Chisquare)
Expand Down
9 changes: 5 additions & 4 deletions hist/hist/src/HFitImpl.cxx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -77,7 +77,7 @@ namespace HFit {
void StoreAndDrawFitFunction(FitObject * h1, TF1 * f1, const ROOT::Fit::DataRange & range, bool, bool, const char *goption);

template <class FitObject>
double ComputeChi2(const FitObject & h1, TF1 &f1, bool useRange, ROOT::Fit::EChisquareType type );
double ComputeChi2(const FitObject & h1, TF1 &f1, bool useRange, ROOT::Fit::EChisquareType type, bool useIntegral = false);



Expand Down Expand Up @@ -1029,22 +1029,23 @@ TFitResultPtr ROOT::Fit::FitObject(THnBase * s1, TF1 *f1 , Foption_t & foption ,
// function to compute the simple chi2 for graphs and histograms


double ROOT::Fit::Chisquare(const TH1 & h1, TF1 & f1, bool useRange, ROOT::Fit::EChisquareType type) {
return HFit::ComputeChi2(h1,f1,useRange, type);
double ROOT::Fit::Chisquare(const TH1 & h1, TF1 & f1, bool useRange, ROOT::Fit::EChisquareType type, bool useIntegral) {
return HFit::ComputeChi2(h1,f1,useRange, type, useIntegral);
}

double ROOT::Fit::Chisquare(const TGraph & g, TF1 & f1, bool useRange) {
return HFit::ComputeChi2(g,f1, useRange, ROOT::Fit::EChisquareType::kNeyman);
}

template<class FitObject>
double HFit::ComputeChi2(const FitObject & obj, TF1 & f1, bool useRange, ROOT::Fit::EChisquareType type ) {
double HFit::ComputeChi2(const FitObject & obj, TF1 & f1, bool useRange, ROOT::Fit::EChisquareType type, bool useIntegral ) {

// implement using the fitting classes
ROOT::Fit::DataOptions opt;
opt.fUseEmpty = (type != ROOT::Fit::EChisquareType::kNeyman); // use empty bin when not using Neyman chisquare (observed error)
opt.fExpErrors = (type == ROOT::Fit::EChisquareType::kPearson);
opt.fErrors1 = (type == ROOT::Fit::EChisquareType::kPearson); // not using observed errors in Pearson chi2
opt.fIntegral = useIntegral; // use bin integral instead of value at bin center

ROOT::Fit::DataRange range;
// get range of function
Expand Down
4 changes: 3 additions & 1 deletion hist/hist/src/TH1.cxx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2495,6 +2495,7 @@ Double_t TH1::Chi2TestX(const TH1* h2, Double_t &chi2, Int_t &ndf, Int_t &igood
/// Use option "R" for restricting the chisquare calculation to the given range of the function
/// Use option "L" for using the chisquare based on the poisson likelihood (Baker-Cousins Chisquare)
/// Use option "P" for using the Pearson chisquare based on the expected bin errors
/// Use option "I" for using the integral of the function in each bin instead of the value at the bin center

Double_t TH1::Chisquare(TF1 * func, Option_t *option) const
{
Expand All @@ -2505,11 +2506,12 @@ Double_t TH1::Chisquare(TF1 * func, Option_t *option) const

TString opt(option); opt.ToUpper();
bool useRange = opt.Contains("R");
bool useIntegral = opt.Contains("I");
ROOT::Fit::EChisquareType type = ROOT::Fit::EChisquareType::kNeyman; // default chi2 with observed error
if (opt.Contains("L")) type = ROOT::Fit::EChisquareType::kPLikeRatio;
else if (opt.Contains("P")) type = ROOT::Fit::EChisquareType::kPearson;

return ROOT::Fit::Chisquare(*this, *func, useRange, type);
return ROOT::Fit::Chisquare(*this, *func, useRange, type, useIntegral);
}

////////////////////////////////////////////////////////////////////////////////
Expand Down
Loading