Hi Christian,
I don't uderstand your problem. With the method I indicated you
can also get events ahead of the current on without any problem.
Example :
tree->GetEntry(15); // Get the current event
Event* evold=new Event(*event); // save the current event
tree->GetEntry(120); // Get another event for mixing
Now you have "evold" and "event" which you can mix as you like.
Obviously you can read-in several other events as well if you want
some more complex mixing procedure.
Cheers,
Nick.
--
Dr. Nick van Eijndhoven mailto:nick@phys.uu.nl http://www.phys.uu.nl/~nick
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Christian Holm Christensen wrote:
>
> Hi Nick,
>
> Nick van Eijndhoven <Nick@phys.uu.nl> wrote concerning
> Re: [ROOT] Mixed events from TChains [Sun, 26 Jan 2003 14:08:36 +0100]
> ----------------------------------------------------------------------
> > Hi Christian,
> > What I normally use is the following :
> >
> > 1) Use GetEntry(ient) to get a certain entry in memory.
> >
> > 2) Then do something like Event* evtold=new Event(*event)
> > to store the current event into the evtold structure.
> >
> > 3) Then do again GetEntry(ient2) to obtain a different
> > event in memory.
> >
> > 4) Now you have 2 structures filled, namely "event"
> > and "evtold" and you can have fun with your mixing :).
>
> That would obviously work, if you just want the previous event
> (basically my work-a-round # 1, though with a cache of exactly one),
> but what if you want events ahead of the current one?
>
> > > I can think of 3 ways of working around this:
> > >
> > > 1) Make the user set a flag that caches the current event, and they
> > > can then call it back from memory storage later on. This obviously
> > > doesn't work if you want to read events ahead of the current one.
> ...
>
> Also, the whole point was to avoid too much copying and
> (de)allocations. Hence, I'd rather there was some other way to do
> this.
>
> Thank you.
>
> Yours,
>
> ___ | Christian Holm Christensen
> |_| | -------------------------------------------------------------
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