allow obs to be specified in extended binding

Author: will-cern

roofit/roofitcore/inc/RooExtendedBinding.h

@@ -14,19 +14,22 @@
 #include "RooAbsReal.h"
 #include "RooRealProxy.h"
 #include "RooCategoryProxy.h"
+#include "RooSetProxy.h"
 #include "RooAbsPdf.h"
 #include "RooAbsCategory.h"
 
 class RooExtendedBinding : public RooAbsReal {
 public:
   RooExtendedBinding() {} ;
   RooExtendedBinding(const char *name, const char *title, RooAbsPdf& _pdf);
+  RooExtendedBinding(const char *name, const char *title, RooAbsPdf& _pdf, const RooArgSet& _obs);
   RooExtendedBinding(const RooExtendedBinding& other, const char* name=nullptr) ;
   TObject* clone(const char* newname=nullptr) const override { return new RooExtendedBinding(*this,newname); }
 
 protected:
 
   RooRealProxy pdf ;
+  RooSetProxy _obsList;
 
   double evaluate() const override ;
 

roofit/roofitcore/src/RooExtendedBinding.cxx

@@ -22,10 +22,18 @@
  {
  }
 
+ RooExtendedBinding::RooExtendedBinding(const char *name, const char *title, RooAbsPdf& _pdf, const RooArgSet& obs) :
+      RooAbsReal(name,title),
+      pdf("pdf","pdf",this,_pdf),
+      _obsList("obsList", "List of observables", this)
+ {
+    _obsList.add(obs);
+ }
 
  RooExtendedBinding::RooExtendedBinding(const RooExtendedBinding& other, const char* name) :
    RooAbsReal(other,name),
-   pdf("pdf",this,other.pdf)
+   pdf("pdf",this,other.pdf),
+   _obsList("obsList", this, other._obsList)
  {
  }
 
@@ -34,7 +42,7 @@
  double RooExtendedBinding::evaluate() const
  {
    // ENTER EXPRESSION IN TERMS OF VARIABLE ARGUMENTS HERE
-   return (const_cast<RooAbsPdf &>(static_cast<RooAbsPdf const&>(pdf.arg()))).expectedEvents(nullptr) ;
+   return (const_cast<RooAbsPdf &>(static_cast<RooAbsPdf const&>(pdf.arg()))).expectedEvents(_obsList.empty() ? nullptr : &_obsList) ;
  }