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HMdcDeDx
This transformation class calculates the "pseudo dEdx" from t2-t1 (time above
threshold)
of all fired drift cells included in one HMdcSeg. The
transformation is performed doing a
normalization of the measured t2-t1 with impact angle and minimum distance to
wire
(MDCCAL2 parameterization) and the algorithm to normalize the
single measurements and
average over all cells included in the segment.
Calculation of dEdx:
Float_t calcDeDx(*HMdcSeg
*,Float_t*,Float_t*,UChar_t*,Float_t*,UChar_t*,Int_t,Int_t)
calculates dEdx of a MDC segment by doing normalization for
impact angle and distance from wire for the fired cells of the segment. The measurements are sorted in increasing order,
the mean and sigma is calculated. Afterwards the truncated mean
is calculated and returned as dEdx. Mean, Sigma, Number of wires before
truncating, truncated mean, truncated mean sigma and number of wires
after truncating can be obtained by the returned pointers.
Different methods can be selected:
vers==0 (default): Input filling from HMdcSeg
(wires, thrown out by the fitter are ignored)
vers==1 : Input filling from HMdcClusFit
(wires, thrown out by the fitter are taken into account)
If the fit has failed (chi2=-1), vers 0 is used
mod==0 : calc dEdx from 1st module in segment
mod==1 : calc dEdx from 2nd module in segment
mod==2 (default) : calc dEdx from whole segment
Settings of the truncated Mean method:
The truncated mean is calculated according to the set window (in sigma units)
(setWindow( Float_t window)) around the mean. For the
calculation of the truncated
mean only drift cells with a dEdx inside the window around the mean (calculated
from
all drift cells of the segment) will be taken into account.
With setMinimumWires(Int_t minwires) the algorithm can be
forced to keep
a minimum number of wires. The method will stop removing drift cells from the
active
sample if the minimum number is reached.
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