Hi,
I whish to know if it was possible to add many variables declared as Double_t in a TList ?
c:\Documents and Settings\alice\Mes documents\Visual Studio Projects\BenchTest\BenchTest\Channel.cpp(286) : error C2440: ‘cast de type’ : impossible de convertir de ‘TObject *’ en 'double’
Aucun contexte dans lequel cette conversion est possible
Thanks
Only objects derived from TObject can be added to a TList.
To add an array of Double_t use a TVectorD object.
Rene
Thanks Rene,
I had never used the “TVectorD”, another aspect which I discover. and a powerfull solution !!!
Best Regards
Hi there,
TVectorD (TVectorT in the reference guide) is limited to 5 elements.
I’m trying to find a way to work with a linked list of doubles in CINT.
I’ve come up with this
TList *mylist = new TList() ;
for (Int_t i=0 ; i<10 ; i++) { mylist->Add(new TParameter<double>(TString::Format("x%02d",i),i*1.)) ; }
for (Int_t i=0 ; i<mylist->Capacity() ; i++) { printf("\n%f",((TParameter<double>*)(mylist->At(i)))->GetVal()) ; }There should be an easier way though.
TIA,
Z
TVectorD can contain as many elements as you wish.
When the vector has 5 or less elements, they are kept internally
on the stack , otherwise on the heap. But that should be of
no concern to the user.
Eddy
Thanks for the correction.
So here comes my stupid question: How do you fill a TVectorD?
I didn’t manage to find any Add()-like method (like in TList or any linked list class).
Thanks,
Z
TVectorD is part of the linear algebra classes and not a container,
so no Add() functions or iterators.
Filling is described in
So this is not a linked list.
Then my question still lies.
Is there any easier way than that proposed above to implement a linked list of doubles working in CINT?
Thanks,
Z
Hi,
Simply use:root [0] #include <list>
root [1] list<double> list;
root [2] list.push_back(1.0);Cheers,
Philippe.
Thanks Philippe.
So there must have been some (nice) improvements in CINT.
I’m pretty sure the following macro did not work in the past:
vector<Double_t> *mylist = new vector<Double_t> ;
mylist->push_back(1.);
mylist->push_back(3.);
for (Int_t i=0 ; i<mylist->size() ; i++) { printf ("\n%f",mylist->at(i)) ; }It does now. So much the better! 
On the contrary, the result is more mitigated with TObjects: 
Double_t x[3] = {1.,2.,3.} ; Double_t y[3] = {1.,2.,3.} ;
vector<TGraph*> *mylist = new vector<TGraph*> ;
mylist->push_back(new TGraph (3,x,y));
mylist->push_back(new TGraph (3,x,y));
printf ("\n%f\n",mylist->at(1)->GetX()[2]) ; /// DOES work in CINT
for (Int_t i=0 ; i<mylist->size() ; i++) { printf ("\n%f",mylist->at(i)->GetX()[0]) ; } /// DOES NOT work in CINT (works fine with ACLIC)This could be overcome using TList at the expense of very irritating necessary “cast wrapping”:
Double_t x[3] = {1.,2.,3.} ; Double_t y[3] = {1.,2.,3.} ;
TList *mylist = new TList() ;
mylist->Add(new TGraph (3,x,y));
mylist->Add(new TGraph (3,x,y));
printf ("\n%f\n",((TGraph*)(mylist->At(1)))->GetX()[2]) ;
for (Int_t i=0 ; i<mylist->GetSize() ; i++) { printf ("\n%f",((TGraph*)(mylist->At(i)))->GetX()[2]) ; }Unless anyone has a nice hint to share… 
TIA,
Z
Hi,
To properly use an STL container you need (in most case) to generate a dictionary for int. For list the dictionary is provided with the ROOT build (and its loading is triggered by the #include). For the STL instances we do not provide a dictionary for (for example vector<TGraph*>) you need to generate it your self with is as simple as writing this small file:// loader.C
#include <vector>
#include "TGraph.h"
#ifdef __MAKECINT__
#pragma link C++ class vector<TGraph*>+;
#endifand load it into your via ACLiC:root [] .L loader.C+
Cheers,
Philippe.
Thank you so much Philippe.
Z
Hi Philippe,
Is there any way to cope with such templates:
[code]#include <TROOT.h>
#include <TClass.h>
#include <TH1.h>
#include <TH2.h>
#ifdef MAKECINT
// #pragma link C++ ?
#endif
template
void MRF_binarizeHisto ( ATH* histo )
{
TString type = TString(histo->Class()->GetName()) ;
if ( ! (type.Contains(“TH1”) || type.Contains(“TH2”) ) ) { fprintf (stderr,"\n\n!!!ERROR in <MRF_binarizeHisto>: bad type!!!\n\n") ; getchar() ; exit(1) ; }
if ( type.Contains(“TH1”) ) { for (Int_t ibin=1 ; ibin<=histo->GetNbinsX(); ibin++) { if ( TMath::Abs(histo->GetBinContent(ibin)) > 0 ) { histo->SetBinContent(ibin,1) ; } } }
else if ( type.Contains(“TH2”) ) { for (Int_t col=1; col<=histo->GetNbinsX(); col++) { for (Int_t row=1; row<=histo->GetNbinsY(); row++) { if ( TMath::Abs(histo->GetBinContent(col,row)) > 0 ) { histo->SetBinContent(col,row,1) ; } } } }
return ;
}[/code]I’ve tried several #pragma statements in vain.
Cheers,
Z
Hi,
As you have it (and thanks to the class hierarchy of the ROOT histograms) you functions does not need to be templated at all! You can simply use:
template void MRF_binarizeHisto ( ATH* histo );
#ifdef MAKECINT
// Both those syntax should work.
#pragma link C++ function MRF_binarizeHisto(TH1F*);
#pragma link C++ function MRF_binarizeHisto;
#endif[/code]
Cheers,
Philippe.
Thanks Philippe.
[quote]Your function does not need to be templated at all![/quote]True only if histo->Class()->GetName() is replaced byhisto->GetClassName()That’s a pity I’d missed that point so far!
[quote]// Both those syntax should work.[/quote]I’d tried the second one actually.
None of them works unfortunatelly 
histo->ClassName() NOT histo->GetClassName()I’m sorry 
Actually you meant:TString type( histo->IsA()->GetName() );and you can even do
if ( ! histo->InheritsFrom( TH1::Class() ) ) {
fprintf (stderr,"\n\n!!!ERROR in <MRF_binarizeHisto>: bad type!!!\n\n") ; getchar() ; exit(1) ;
}
if ( histo->InheritsFrom( TH2::Class() ) ) {
// 2D histogram stuff
} else {
// 1D histogram stuff
}
Cheers,
Philippe.
Thx Philippe.
Any clue for the #pragma thing?
Hi,
With#ifdef __MAKECINT__
#pragma link C++ function _MRF_binarizeHisto_(TH1*);
#endif
I get the correct dictionary:
root [0] .L tt.C+
Info in <TUnixSystem::ACLiC>: creating shared library /private/var/tmp/./tt_C.so
root [1] .function > res01
root [2] .! grep MRF res01
tt_C.so -1:-1 0 public: void _MRF_binarizeHisto_(TH1* histo);
Cheers,
Philippe.
Thanks Philippe.
Indeed you get the correct dictionary if the prototype of the function is declared before the #pragma block.
Attached’s a complete working example using the template way (mrf_template.C) and the “plain/smart” way (mrf.C). Just type .x ztest.cpp[+]As the function call in ztest.cpp has to be the same in both cases* (namely MRF_binarizeHisto()), there’s no point in implementing the template case indeed.
Cheers,
Z