[d2n-analysis-talk] replay_det_BB.C: error messages and scalers

[Brad Sawatzky]

On Wed, 03 Mar 2010, Diana Parno wrote:

[ . . . ]
> I'm using my own replay_det_BB.odef file with the idea of having a couple 
> of trees just for the scaler data. The definition of said trees is at the 
> bottom of /home/dseymour/d2n-replay/replay/replay_det_BB.odef -- it starts 
> out, for example,
[ . . . ]
> Any ideas why the bbite tree wouldn't be filled? (evbbite isn't,
> either, for my data.) Or where this null bbite_u1cnt data is coming
> from?

The scaler classes were not instantiated in replay_det_BB.C.  I added
them to my script:
  /home/brads/d2n-replay/replay/replay_det_BB.C

> At this point I've been fairly well trained to quit the analyzer in
> between replays. I think we figured out a few months ago that the
> modules aren't cleaning up after themselves very well -- this is why
> we wound up commenting out the lines
> 
> /*  gHaApps->Delete();
>      gHaPhysics->Delete();
>      gHaScalers->Delete();
>      analyzer->Close();
> */
> 
> in our standard version of ReplayCore.C, right?

Yeah...  bit of a hack, unfortunately.

[ . . . ]
> Does anyone have/know of any documentation where I can just get a list
> of what variables exist and what they mean, for LHRS and/or for
> BBITE??  Suppose I just *think* I'm looking at the right variables ...
> is there any way to pick the right ones apart from (1) trial and error
> or (2) pestering other people for their code? Some variables obviously
> follow conventions, e.g. for particular shower blocks, but what if you
> don't know the convention for the particular X you're looking for?

There are two challenges here.  You have to know (a) what analyzer
variable names you want, and the analyzer has to know (b) what hardware
(or EPICS channel name) to look at to fill said variables.

(A) is best worked out by talking to other 'experts' and/or looking at
    the source code.  I hacked up a script a while back to list the
    tree variables defined in the the analyzer code:
    https://hallaweb.jlab.org/wiki/index.php/List_of_Analyzer_ROOT_variable_names

(B) relies on documentation from the run (Halog, wiki, etc) to be correct.

If it was easy, we wouldn't need PhD's to do all this stuff :-/

-- Brad

-- 
Brad Sawatzky, PhD <brads at jlab.org>  -<>-  Jefferson Lab / Hall C / C111
  Ph: 757-269-5947 -<>- Pager: 757-584-5947 -<>- Fax: 757-269-7848
The most exciting phrase to hear in science, the one that heralds new
  discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov