Splitlevel and vectors in classes

ROOT
1

I have a custom class (inheriting from TObject) which has as a member a vector of another custom class, which itself has a member of a third custom class. See header file below:

#include <iostream>
#include <vector>
#include "TObject.h"

class sublevel:public TObject{
public:
   double one;
private:
   ClassDef(sublevel,1);
};

class toplevel:public TObject{
public:
   int a;
   std::vector<sublevel> b;
private:
   ClassDef(toplevel,1);
};


class testClass :public TObject
{

public:
   testClass();
   void ClearAll();
   int someNumber;
   std::vector<toplevel> tops;


private:
   ClassDef( testClass, 1 )
};

I make class dictionaries for all these things with a LinkDef:

#include <vector>
#include <string>
#ifdef __CINT__
#pragma link C++ nestedclasses;
#pragma link C++ class testClass+;
#pragma link C++ class sublevel+;
#pragma link C++ class vector<sublevel>+;
#pragma link C++ class toplevel+;
#pragma link C++ class vector<toplevel>+;
#endif

and I can compile an executable with this.

I then make a tree in my executable with one branch of type testClass, and splitlevel 99.

When I look at this tree on the root command line, I see:

[code]******************************************************************************
*Tree :tree : tree *
*Entries : 100 : Total = 14568 bytes File Size = 3944 *

  •    :          : Tree compression factor =   3.40                       *

*Branch :event *
*Entries : 100 : BranchElement (see below) *
…
*Br 0 :fUniqueID : UInt_t *
*Entries : 100 : Total Size= 970 bytes File Size = 99 *
*Baskets : 1 : Basket Size= 32000 bytes Compression= 4.81 *
…
*Br 1 :fBits : UInt_t *
*Entries : 100 : Total Size= 1358 bytes File Size = 286 *
*Baskets : 1 : Basket Size= 32000 bytes Compression= 3.08 *
…
*Br 2 :someNumber : Int_t *
*Entries : 100 : Total Size= 975 bytes File Size = 249 *
*Baskets : 1 : Basket Size= 32000 bytes Compression= 1.92 *
…
*Br 3 :tops : Int_t tops_ *
*Entries : 100 : Total Size= 4050 bytes File Size = 285 *
*Baskets : 1 : Basket Size= 32000 bytes Compression= 3.08 *
…
*Br 4 :tops.fUniqueID : UInt_t fUniqueID[tops_] *
*Entries : 100 : Total Size= 1477 bytes File Size = 294 *
*Baskets : 1 : Basket Size= 32000 bytes Compression= 3.02 *
…
*Br 5 :tops.fBits : UInt_t fBits[tops_] *
*Entries : 100 : Total Size= 1457 bytes File Size = 292 *
*Baskets : 1 : Basket Size= 32000 bytes Compression= 3.03 *
…
*Br 6 :tops.a : Int_t a[tops_] *
*Entries : 100 : Total Size= 1437 bytes File Size = 298 *
*Baskets : 1 : Basket Size= 32000 bytes Compression= 2.96 *
…
*Br 7 :tops.b : vector b[tops_] *
*Entries : 100 : Total Size= 4037 bytes File Size = 803 *
*Baskets : 1 : Basket Size= 32000 bytes Compression= 4.33 *
…
[/code]

That, is, the vector of the sublevel class doesn’t get split any further; there is no branch tops.b.one. (Nevertheless, the command tree->Draw(“tops.b.one”) works and draws the appropriate thing.)

Is there a way to get this splitting to happen down to the “tops.b.one” level? I would like this, as I want to be able to use MakeClass on this tree, and without that splitting, the sublevel information can’t be accessed with MakeClass.

I have tested that if I only have a single sublevel object within toplevel, the splitting does happen, so I assume that this has something to do with the edicts found in 14.10.1.3 Rules for Splitting, but I’m not quite sure if the vector is considered a pointer from the point of view of this issue—and if so, why does drawing tops.b.one work?

I am using ROOT 5.34/26; suggestions to go to ROOT 6 are not helpful, as the version is constrained by external factors.

2

Hi,

Unfortunately nested collection can not be split (so far the attempt to design meta-data necessary to support this having too complicated).

For this purpose, you can use MakeProxy instead, it should give access also to the nested collection.

Cheers,
Philippe.

3

Thank you for the swift and helpful reply!