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Problems with GEANE and trackbase Fri, 07 March 2008 02:40
 Sebastian Neubert Messages: 282Registered: March 2006 Location: Munich first-grade participant From: *dip.t-dialin.net
Hi!

After some hours of fruitless debugging I came back to the following problem:

I have a script (look at recotasks/demo/geaneDemo.C) with these lines:

```
// Setup a trackrep which uses geane
CbmGeanePro* gePro=new CbmGeanePro();

TVector3 pos(0.1,0.1,0.1);
TVector3 mom(0.1,0.1,1.);
TVector3 poserr=TVector3(0.1,0.1,0.1);
TVector3 momerr=0.2*mom;

DetPlane initplane(TVector3(pos),TVector3(1.,0.,0.),TVector3(0.,1.,0.));
double q=-1;

CbmTrackParP 	par(pos,mom,poserr,momerr,q,
initplane.getO(),initplane.getU(),initplane.getV());
par.Print();
```

Note that px=py!
These lines lead to the following output:

```======================================================
Position : (0.1, 0.1, 0.1)
Slopes : dx/dz = 0.0008, dy/dz = 0.0004
q/p = -0.99
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
```

Note that dx/dz!=dy/dz. Something is going really wrong!

When I tried to track the problem I stumbled over the following lines. What the hack is meant with y-z-plane???

```//      Tranform error matrix
//      FROM   MASTER                  VARIABLES (px, py,pz, x, y, z)
//      TO     SD (transverse or local system)
//                                     VARIABLES (1/p, v', w', v, w)
//
//      Method: the MARS system is considered as a detector system SD1 with
//              y-z as the detector plane. Hence eq (79) of the
//              report CMS 2006/001 is used to go from canonical to SD1 variables.
//              Then, the SD1 to SD routine is used.
//              In this way the track length variation and the magnetic field
//              effects are correctly taken into account.
//
//      Authors: A. Rotondi and A. Fontana (July 2007)
```

Another issue: trackbase uses the magnetic field. It get's this from the CbmRun singleton object. This construct creates nasty dependencies which make it unnecessarily hard to write tests for the code. It was always advertized that PandaRoot is getting rid of the cross-dependencies.

Best Regards, Sebastian.

PS: Please allow me the comment, that I am quite disappointed, that after one year this is still not in order! And that I have to dig into other people's code while at the same time apparently nobody from the geane community ever even had a look at GeaneTrackRep. It is YOUR responsibility that this works!

I needed to say that. Now let's go and get the damn tracking running!

Sebastian Neubert
Technische Universität München
Department Physik E18
sneubert@e18.physik.tu-muenchen.de
tel: +49-8928912592

 Problems with GEANE and trackbase By: Sebastian Neubert on Fri, 07 March 2008 02:40 Re: Problems with GEANE and trackbase By: Mohammad Al-Turany on Fri, 07 March 2008 09:35 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Fri, 07 March 2008 10:11 Re: Problems with GEANE and trackbase By: Andrea Fontana on Tue, 11 March 2008 11:12 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Tue, 11 March 2008 14:02 Re: Problems with GEANE and trackbase By: Andrea Fontana on Tue, 11 March 2008 15:26 Re: Problems with GEANE and trackbase By: Mohammad Al-Turany on Tue, 11 March 2008 14:14 Re: Problems with GEANE and trackbase By: Andrea Fontana on Tue, 11 March 2008 17:09 Re: Problems with GEANE and trackbase By: Mohammad Al-Turany on Tue, 11 March 2008 17:11 Re: Problems with GEANE and trackbase By: Mohammad Al-Turany on Tue, 18 March 2008 18:21 Re: Problems with GEANE and trackbase By: Mohammad Al-Turany on Wed, 19 March 2008 11:21 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Wed, 19 March 2008 12:01 Re: Problems with GEANE and trackbase By: Lia Lavezzi on Wed, 19 March 2008 12:36 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Tue, 08 April 2008 12:29 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Tue, 08 April 2008 13:30 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Tue, 08 April 2008 14:27 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Tue, 08 April 2008 15:52 Re: Problems with GEANE and trackbase By: Lia Lavezzi on Tue, 08 April 2008 15:59 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Wed, 09 April 2008 12:12 Re: Problems with GEANE and trackbase By: Lia Lavezzi on Wed, 09 April 2008 15:46 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Wed, 09 April 2008 17:09 Re: Problems with GEANE and trackbase By: Sebastian Neubert on Wed, 09 April 2008 17:52 Re: Problems with GEANE and trackbase By: Lia Lavezzi on Thu, 15 May 2008 17:25
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