>
> One thing about your update: If you have sequences with negative
> adc-values, i.e. if you for some reason do not run the PreProcessor or
> similar, then you may end up with an fMeanPad that is outside ( minPad <=
> fMeanPad || fMeanPad <=maxPad ) causing your first assert() in
> BrTPCCluster->Build() to fail. This caused me some headaches just now... I
> think maybe this should be changed, since neg. adc-values may well be a
> feature of unprocessed sequences we might want to work with (with all the
> problems that gives...). What do you think?
>
Methinks negative adc values are a feature of the raw data.
The ADC values you see are ("real ADC values from the TPC" - "pedestal").
The pedestal is determined as an average adc value, so non-compressed
raw data will have half of the ADC values negative (below pedestal).
Because the tpc data compression keeps two adc time bins before and after
each "peak", by definition these extra time bins will be below the
compression threshold and could well be below the pedestal, that is, negative.
--
Konstantin Olchanski
Physics Department, Brookhaven National Laboratory, Long Island, New York
olchansk@bnl.gov
This archive was generated by hypermail 2b29 : Wed Oct 04 2000 - 10:50:09 EDT