From mverzocc@fnal.gov Fri Apr 30 16:54:02 2004 Date: Thu, 22 Apr 2004 18:13:28 -0500 From: Marco Verzocchi To: Gordon Watts Cc: d0dfwg@fnal.gov, Terry Wyatt Subject: Re: Comments from the WZ group on data format issues [ The following text is in the "ISO-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] Hi again, > > I assume you are talking about finer control than just dropping >branches here. For example, if you wanted to drop branches you could >drop all the jet information at once. You would like to, say, be able to >drop the jet eta from the jet information (ok, dumb example, but that is >the level you are talking about). > > > >> I don't think that this is acceptable when it means that the porting >>to the >>framework is done several months after the availability of the >> >> >algorithm > > >>inside ROOT. >> >> Yes I really mean finer control at the level of branches (and as a starter in the TMBtree - )I should check whether that is there already - I would like to save only Jet X and EMobject Y, instead of several copies of Jet A, Jet B,.....). But I think that to make a ROOT format really user friendly any change (in negative) to the quantities saved in the ROOT format should be RCP (or similar stuff) driven. So that a user who wants to drop "eta" could do it without recompiling...... > > If the algorithm is developed inside root, it will be "available" by >definition first in root. If we have a common root format, and the >translation infrastructure has been already generated, then it will be >available in both the framework and root at approximately the same time. >The author will, however, have to write a chunk to hold the results and >(the hardest part in a scheme like this) make connections back to the >parent objects. > > You're earlier point about how long it takes the "wrapper" to convert >from TMB to this root format for use in the framework is well taken. I >don't know how long it is, but I know it is tiny compared to the current >running of reco. I don't, for example, know how long it is compared to >the current running of d0correct. I also know it is tiny compared to the >time it takes to run the root based vertexing. > > > > Another thing which worries me a lot about wrappers is that they need to be done properly and maintained. And if you had tried to look at the wrappers which were available for a while to make sure that the EM corrections could be used from the TMBtree you would have started to cry. Imagine calling a FORTRAN function without having common blocks and passing 25 parameters. Recipee for disasters...... A lot of people think that wrappers are easy and don't represent problems, but when you start having complex objects your wrapper starts to have to deal with a lot of variables..... Not all the wrappers are so easy and silly like the JES methods..... Cheers Marco