TTrees in Windows

ROOT
1

I am using ROOT version 4.03/04 developing a Windows app in Visual Studio .NET 2003. I’m having a problem writing TTrees to File or receiving TTrees over sockets. I can however construct TTrees in memory and manipulate them. I believe the underlying problem is with streamers. The error I receive when writing to file is:

“Warning in TClass::TClass: no dictionary for the class TTree is available”

Note, I do not have this same problem in Linux. Any help would be greatly appreciated.

Kevin

2

Kevin,

Could you send the shortest possible script reproducing the problem?

Rene

3

Hi Brun,

If I have a test.root file with a TTree named “test”. I run:

///
TFile f(“test.root”,“READ”);
TTree* t = (TTree*)f.Get(“test”); //exception thrown here
f.Close();
///

Note that I’m using visual studio in Windows and I’ve included:
libCore.lib
libWin32gdk.lib
libTree.lib
libMatrix.lib

Thanks.

Kevin

4

Are you building your own application? see example of a small test
program in $ROOTSYS/test/hsimple.cxx.
In thois directory you can run make to see how this application is built.

Rene

5

Hi Rene,

Figured it out… weird problem with Visual Studio I guess. I have to create an instance of TTree before I try to access one from file. Then it works.
Thanks for prompt responses!

Kevin