Adding array of struct to a Tree

rikmer · November 15, 2010, 4:06pm

Hi,

next question regarding Trees. How do I add an array of a struct to a Tree?
If I have, eg:

[code]TTree* testTree = new Tree(“something”,“TestTree”);

struct {
int test2;
double test3;
} test1[20][30];

testTree->Branch(“test1”,&test1, “test1[20]/ XX”)
testTree->Fill()
[/code]

What should I use for the XX in the code, because it is no standard data type?

BR

pcanal · November 15, 2010, 5:46pm

Hi,

The leaflist technique to add branch does NOT support array of struct (but it support struct of arrays).[code]
TTree* testTree = new Tree(“something”,“TestTree”);
struct {
int test2[20][30]
double test3[20][30]
} test1;

testTree->Branch(“test2”,&test1.test2, “test2[20][30]/I”);
testTree->Branch(“test3”,&test1.test3, “test3[20][30]/D”);
testTree->Fill();[/code]

I strongly suggest that you move to using the object based technique to add branch:[code]// Script.C
class test1 {
public:
test1() : test2(0), test3(0) []
int test2;
double test3;
};
class Holder {
public:
test1 values[20][30];
};

TTree createTree() {
TTree testTree = new Tree(“something”,“TestTree”);
Holder holder;
testTree->Branch(“event.”,&holder);
testTree->Fill();
testTree->ResetBranchAddresses();
return testTree;
}[/code]and use with ACLiCroot [] .L Script.C+

Cheers,
Philippe.

rikmer · November 16, 2010, 1:13pm

Thank’s so far.
If I am using an external compiler (gcc) I will have to generate a dictionary with rootcint to make the object based technique work, I guess. Am I right?

BR

pcanal · November 16, 2010, 1:21pm

Hi,

[quote] I will have to generate a dictionary with rootcint to make the object based technique work[/quote]Yes.

Philippe.

rikmer · November 16, 2010, 1:45pm

Okay. One question left.
If I look at your first code example would it also be possible to add the struct like this?

[code]TTree* testTree = new Tree(“something”,“TestTree”);
struct {
int test2[20][30]
double test3[20][30]
} test1;

testTree->Branch(“test2”,&test1, “test2[20]/I:test3[20]/D”);
testTree->Fill();[/code]

Please say yes.

BR

pcanal · November 16, 2010, 1:50pm

Hi,

[quote]Please say yes.[/quote]Well actually the answer is no (in particular because the 2 declared sizes do not match) but the first code example I gave does not require a dictionary (so I do not see why you would need to use or prefer the code in your last question).

Cheers,
Philippe.

rikmer · November 16, 2010, 2:00pm

The thing is that I have a lot of structs with also a lot of internal arrays and I wonder now if I have to read in and write out all of these internal arrays seperately, because I am exchanging data between my classes with Trees.
I cant do this either?

[code]TTree* testTree = new Tree(“something”,“TestTree”);
struct {
int test2[20][30]
double test3[20][30]
} test1;

testTree->Branch(“test2”,&test1, “test2[20][30]/I:test3[20][30]/D”);
testTree->Fill();[/code]
And I guess it is also not possible to read the data out of the Tree, which is generated in your first code example, like this:

[code]struct {
int test2[20][30]
double test3[20][30]
} test4;

testTree->SetBranchAddress(“test1”, &test4);
testTree->GetEntry(0);
[/code]

BR

pcanal · November 16, 2010, 3:13pm

[quote]The thing is that I have a lot of structs with also a lot of internal arrays[/quote]Then it would be simplier and less error-prone to simply create dictionaries for those structs. This is as simple as writing a linkdef.h file://struct_linkdef.h #ifdef __MAKECINT__ #pragma link C++ class test1+; #pragma link C++ class test2+; etc. #endifand adding to your Makefile something like:[code]MyDict.cxx: $(HEADERS) struct_linkdef.h
[TAB] rootcint -f $@ -c $(CXXFLAGS) -p $^

libMyLib.so: MyDict.cxx $(SOURCES)
[TAB] g++ -shared -o$@ root-config --ldflags $(CXXFLAGS) -I$(ROOTSYS)/include $^[/code]

Cheers,
Philippe.

PS. [quote]And I guess it is also not possible to read the data out of the Tree, which is generated in your first code example, like this:[/quote]that’s right you can not.

[quote]I cant do this either? … “test2[20][30]/I:test3[20][30]/D”[/quote]It will probably work but I do not recommend it.

rikmer · November 16, 2010, 3:44pm

Thank you very much. Some question remain not crystal clear. I am sorry to bug you even more but I am kind of brain dead today.

So I only have to create the header file and add it to my make file?

Do I also have to create a mydict.cxx file and add it to the make file?

Where should the linkdef.h be included?

Could you please give me again one code example on how I will use the Trees afterwards?

Did I understand it right that when this dictionary is created that I can use the struct as a single object but it is still not possible to add an array of this object to a Tree?

BR

pcanal · November 16, 2010, 4:19pm

Hi,

Please see root.cern.ch/drupal/faq#n676
and root.cern.ch/download/doc/15AddingaClass.pdf

[quote]So I only have to create the header file and add it to my make file?[/quote]Yes.

[quote]Do I also have to create a mydict.cxx file and add it to the make file?[/quote]Yes for example using a variation of the Makefile code snippet I provided.

[quote]Where should the linkdef.h be included?[/quote]It should only be used as an argument to the rootcint command.

[quote]Could you please give me again one code example on how I will use the Trees afterwards?
[/quote]

testTree->SetBranchAddress("test1", &test4); testTree->GetEntry(0);

[quote]Did I understand it right that when this dictionary is created that I can use the struct as a single object but it is still not possible to add an array of this object to a Tree?[/quote]Correct. But you can add a collection of those objects (either a TClonesArray if you inherit from TObject or std::vector if you generate the dictionary for the vector class).

Cheers,.
Philippe.

rikmer · November 16, 2010, 4:50pm

Thank you very much! I will try your suggestions.

BR

rikmer · November 17, 2010, 3:56pm

Hmmm. Regretfully some problems again. When I try to generate the dictionary I get those errors.

$ rootcint -f Dict.cpp -c TDummy1.h TDummy2.h linkDef.h Error: link requested for unknown class teststruct1 linkDef.h:3: Error: link requested for unknown class teststruct2 linkDef.h:4: Error: link requested for unknown class linkDef G__auto4142LinkDef.h:9: Warning: Error occurred during reading source files Warning: Error occurred during dictionary source generation !!!Removing Dict.cpp Dict.h !!! Error: rootcint: error loading headers...
The TDummy1.h file looks like this:

[code]#ifndef TDUMMY1_H
#define TDUMMY1_H

#include
#include

#include <TTree.h>

class TDummy1
{
public:
typedef struct {
int testint1;
int testintarray1D1[40];
int testintarray2D1[40][40];
} teststruct1;

teststruct1 teststruct;

teststruct1 teststructarray1D1[40];

//teststruct1 teststructarray2D1[40][40];

std::vector<teststruct1> vteststruct1D1;
std::vector<std::vector<teststruct1> > vteststruct2D1;

TTree* outputTree;
void fillData();
void transVector();
void writeTree();
TDummy1();

};

#endif // TDUMMY1_H[/code]
The TDummy2.h the same but instead of teststruct1 it is teststruct2.

The linkDef.h:

//linkDef.h #ifdef __MAKECINT__ #pragma link C++ class teststruct1+; #pragma link C++ class teststruct2+; #pragma link C++ class vector<teststruct1>+; #pragma link C++ class vector<vector<teststruct1> >+; #pragma link C++ class vector<teststruct2>+; #pragma link C++ class vector<vector<teststruct2> >+; #endif

Any advice?

pcanal · November 17, 2010, 4:00pm

Hi,

[quote]Error: link requested for unknown class teststruct1 linkDef.h:3:[/quote]Is an accurate error isn’t it? Didn’t you mean to talk about ‘TDummy1::teststruct1’ ?

Cheers,
Philippe.

rikmer · November 17, 2010, 4:14pm

So I should write TDummy1::teststruct1 instead of teststruct1 in the linkDef.h? Is this correct? I hope I did understand you right.

BR

pcanal · November 17, 2010, 4:17pm

Yes, in the linkdef you need to use the fully qualified name of all the classes.

Philippe.

rikmer · November 17, 2010, 4:21pm

Thank you. Slowly it is getting more and more clear. But I get a different error now.
My linkDef.h no reads like this,

//linkDef.h #ifdef __MAKECINT__ #pragma link C++ class TDummy1::teststruct1+; #pragma link C++ class TDummy2::teststruct2+; #pragma link C++ class vector<TDummy1::teststruct1>+; #pragma link C++ class vector<vector<TDummy1::teststruct1> >+; #pragma link C++ class vector<TDummy2::teststruct2>+; #pragma link C++ class vector<vector<TDummy2::teststruct2> >+; #endif
and I get …

$ rootcint -f Dict.cpp -c TDummy1.h TDummy2.h linkDef.h Error: link requested for unknown class linkDef G__auto4172LinkDef.h:9: Warning: Error occurred during reading source files Warning: Error occurred during dictionary source generation !!!Removing Dict.cpp Dict.h !!! Error: rootcint: error loading headers...

Where did I forget something again?

BR

rikmer · November 17, 2010, 4:47pm

Never mind. In this case I found the answer myself. It is a wonder .
One has to name the definition header file LinkDef.h. It is case sensitive.
But if I try to compile the whole thing (added Dict.cpp to my make file). I get a bunch of errors.

$ make [ 25%] Building CXX object CMakeFiles/dictionary_test.dir/Dict.cpp.o /home/adonai/projects/dictionary_test/Dict.cpp: In function ‘ROOT::TGenericClassInfo* ROOT::GenerateInitInstanceLocal(const TDummy1::teststruct1*)’: /home/adonai/projects/dictionary_test/Dict.cpp:52: error: ‘ROOT::Shadow::TDummy1’ has not been declared /home/adonai/projects/dictionary_test/Dict.cpp: In function ‘ROOT::TGenericClassInfo* ROOT::GenerateInitInstanceLocal(const TDummy2::teststruct2*)’: /home/adonai/projects/dictionary_test/Dict.cpp:94: error: ‘ROOT::Shadow::TDummy2’ has not been declared /home/adonai/projects/dictionary_test/Dict.cpp: In function ‘void ROOT::TDummy1cLcLteststruct1_ShowMembers(void*, TMemberInspector&)’: /home/adonai/projects/dictionary_test/Dict.cpp:128: error: ‘ROOT::Shadow::TDummy1’ has not been declared /home/adonai/projects/dictionary_test/Dict.cpp:128: error: expected initializer before ‘ShadowClass’ /home/adonai/projects/dictionary_test/Dict.cpp:129: error: ‘ShadowClass’ was not declared in this scope /home/adonai/projects/dictionary_test/Dict.cpp:129: error: ‘sobj’ was not declared in this scope /home/adonai/projects/dictionary_test/Dict.cpp:129: error: expected primary-expression before ‘)’ token /home/adonai/projects/dictionary_test/Dict.cpp:129: error: expected ‘;’ before ‘obj’ /home/adonai/projects/dictionary_test/Dict.cpp: In function ‘void ROOT::TDummy2cLcLteststruct2_ShowMembers(void*, TMemberInspector&)’: /home/adonai/projects/dictionary_test/Dict.cpp:167: error: ‘ROOT::Shadow::TDummy2’ has not been declared /home/adonai/projects/dictionary_test/Dict.cpp:167: error: expected initializer before ‘ShadowClass’ /home/adonai/projects/dictionary_test/Dict.cpp:168: error: ‘ShadowClass’ was not declared in this scope /home/adonai/projects/dictionary_test/Dict.cpp:168: error: ‘sobj’ was not declared in this scope /home/adonai/projects/dictionary_test/Dict.cpp:168: error: expected primary-expression before ‘)’ token /home/adonai/projects/dictionary_test/Dict.cpp:168: error: expected ‘;’ before ‘obj’ make[2]: *** [CMakeFiles/dictionary_test.dir/Dict.cpp.o] Fehler 1 make[1]: *** [CMakeFiles/dictionary_test.dir/all] Fehler 2 make: *** [all] Fehler 2

I don’t know.

BR

pcanal · November 18, 2010, 1:49pm

HI,

You need to either add#pragma link C++ class TDummy1+; to the linkdef file or add ClassDef(teststruct1,2); inside the declaration of the class teststruct1.

Cheers,
Philippe.

rikmer · November 18, 2010, 2:22pm

Thank you very much again. Just a moment before you posted, I was to post that it compiled now. I modified my LinkDef.h file:

//linkDef.h #ifdef __MAKECINT__ #pragma link C++ class TDummy1+; #pragma link C++ class TDummy2+; #pragma link C++ class TDummy1::teststruct1+; #pragma link C++ class TDummy2::teststruct2+; #pragma link C++ class vector<teststruct1>+; #pragma link C++ class vector<vector<teststruct1> >+; #pragma link C++ class vector<teststruct2>+; #pragma link C++ class vector<vector<teststruct2> >+; #endif
and also the TDummy classes (added ClassDef and ClassImp) EDIT: as well as #include "RTypes.h"
TDummy1.h:

[code]#ifndef TDUMMY1_H
#define TDUMMY1_H

#include
#include

#include “Rtypes.h”
#include “TTree.h”

class TDummy1
{
public:
typedef struct teststruct1 {
int testint1;
int testintarray1D1[40];
int testintarray2D1[40][40];
} teststruct1;

teststruct1 teststruct;

teststruct1 teststructarray1D1[40];

//teststruct1 teststructarray2D1[40][40];

typedef std::vector<teststruct1> vteststruct1D;
typedef std::vector<std::vector<teststruct1> > vteststruct2D;

vteststruct1D vteststruct1D1;
vteststruct2D vteststruct2D1;

public:

TTree* outputTree;

void fillData();
void transVector();
void writeTree();
TDummy1();
  
ClassDef(TDummy1,1);

};

#endif // TDUMMY1_H[/code]
TDummy1.cpp (first lines):

[code]#include “TDummy1.h”

ClassImp(TDummy1);[/code]

Does this look correct?

BR

pcanal · November 18, 2010, 3:36pm

[quote]Does this look correct?[/quote]Not quite yet.
I think you need to use:#pragma link C++ class vector<TDummy1::teststruct1>+; #pragma link C++ class vector<vector<TDummy1::teststruct1> >+; #pragma link C++ class vector<TDummy2::teststruct2>+; #pragma link C++ class vector<vector<TDummy2::teststruct2> >+;

Cheers,
Philippe