in THcScintillatorPlane

  in calculation of drift chamber start time

  Pulse height corrected times saved in THcHodoHit objects.
  PulseHeightCorrection method renamed to EstimateFocalPlaneTimes
    because the pulse height correction is now done in the
    ProcessHitsMethod.

   Don't repeat comparisons of tdc values
   with fScinTdcMin and fScinTdcMax because hits only get added to
   fHodoHits (and previously fPosTDCHits, fNegTDCHits, ...) if
   the times are within these ranges.
  In THcHodoscop, remove members of fTOFPInfo that are just used
   locally.

  Eliminate usage of GetParent() many times every event.

  Move hodo_slop retrieval to THcHodoscope
  Get fPosCenter array length from fNelem instead of fixing length at 16
  Remove now unneeded THcScintillatorPlane creation method

  For the most part this is making sure that the loop variable in
  a for loop is of the same type as the variable that it is compared
  against (Often a UInt_t).

This reverts commit e9ce1040.

Conflicts:
	src/THcHallCSpectrometer.cxx

  For the most part this is making sure that the loop variable in
  a for loop is of the same type as the variable that it is compared
  against (Often a UInt_t).

Goldent track is moved to THcHallCSpectrometer::TrackCalc()
  if  fSelUsingScin == 0 then golden track is calculated just
  like podd. i.e. it is the first track with minimum chi2/ndf
  with sorting ON

  if fSelUsingScin == 1 then golden track is calculetd just like
  engine/HTRACKING/h_select_best_track_using_scin.h. This method
  gives the best track with minimum value of chi2/ndf but with
  additional cuts on the tracks. These cuts are on dedx, beta
  and on energy.

  This commit also corrects and modifies the beta code written
  in the THcHodoscope::FineProcess

  At this point we have godlend track and in additoion to
  previous vlues the following values are set to a track:
  Energy, beta, chi2 of beta and dedx[track][first hit].

NOTE: For some tracks we have large differences in value of chi
      square between ENGINE and hcana and this is already
      discussed in the last group meeting. Following emails are
      exchanged regarding this difference of chisquare.

email to Mark:

Hi Mark,
I tried to trace the origin of difference of the chi square value between
ENGINE and hcana. Please see the attached file, it has long table which I
cannot present in this email. Or you can see the file at the following
link, thanks.

https://userweb.jlab.org/~zahmed/chi2diff.txt

Ahmed

Mark's reply:
Ahmed,
        Thanks. I agree with what you see, but there is also another reason
for the difference. For the space point in ch2 the engine and hcana
choose different left/right combinations. That is why you see the large
jump in the summed chi2 from planes 9 and 10. The two codes pick
different left/right because there is a cut on the difference between the
measured stub xp and an expected xp = sp->GetX()/875  and one code has a combination
slightly below the cut value and the other slightly above. I do not see a way
to make the codes agree more exactly since the stub fitting involves a matrix
inversion.

                Cheers,
                       Mark

This commmit is only for Beta. THcHodoscope is modified and few
bugs are fixed. I will not make pull request for this commit.
Pull request will be made after the completion of Golden track
in THcHallCSpectrometer.

Conversion of h_tof.f to THcHodoscope::CoarseProcess method.

 Quick summary of third version at  branch zafar1:

 New functions in THcScintillatorPlane.h
 ---------------------------------------
    TClonesArray* GetPosADC() { return fPosADCHits;}; // Ahmed
    TClonesArray* GetNegADC() { return fNegADCHits;}; // Ahmed
    TClonesArray* GetPosTDC() { return fPosTDCHits;}; // Ahmed
    TClonesArray* GetNegTDC() { return fNegTDCHits;}; // Ahmed

 New data members in THcHodoscope.h
 ----------------------------------
    TClonesArray* scinPosADC; // Ahmed
    TClonesArray* scinNegADC; // Ahmed
    TClonesArray* scinPosTDC; // Ahmed
    TClonesArray* scinNegTDC; // Ahmed

 Action in THcHodoscope::CoarseProcess
 -------------------------------------
 scinPosADC = fPlanes[ip]-GetPosADC();
 hitPaddle  = (THcSignalHit*)scinPosADC->At(ihit))->GetPaddleNumber()-1;

The arrays are  frPosTDCHits, frNegTDCHits,frPosADCHits and frNegADCHits
There are filled in THcScintillatorPlane:ProcessHits
2) Also modified THcScintillatorPlane::ProcessHits explicitly set variable
padnum=hit->fCounter and index=padnum-1 so the the TClone arrays for
scintillator variable set padnum=1,16 while the index=0-15
Want pdnum=1-16 because it is used in a hitogram fo counts versus
paddle number
3) Because of change to filling PaddleNumber in ProcessHits had
to modify THcScintillatorPlane::PulseHeightCorrection so the
index variable "j" is set to etPaddleNumber()-1 .

GN: finished debugging the hodoscope start time calculation. Results match 1-to-1 the corresponding "engine" result.

Calculating pulse height correction for the hodoscope.
Calculating focal plane times for each scintillator plane - (in THcScintillatorPlane)
Calculating hodoscope start time (average of fp times) - (in THcHodoscope)

hodoscope start time.

xhodo.pos and xhodo.param
THcHodoscope generally holds:
- singular variables (i.e. central path through the spectrometer, min/max limits for the ADCs, TDCs, etc.)
- "padded arrays" (i.e. look at the plane with the most scintillators, allocate and array that has max_no_scint * no_of_planes - these are mostly found in the .param file)
THcScintillatorPlane generally holds:
- simple variables containing plane-specific info (z-position, scintillator size and spacing)
- arrays sized appropirately for the specific plane (i.e. individual x (or y) positions for all scintillators in a plane, signal propagation speed in the paddle, etc.)

Use cut file to determine what is a pedestal event.  Pedestal events
only proceed to Decode.
In Decode (Just THcHodoscope for now) loop through each plane and accumulate
pedestal data.  Calculate the pedestals at the first non-pedestal event.
Pedestals are just calculated, but nothing is done with them.

add simple code to register ADC and TDC hits into global
variables so that hit maps can be made.

Add ThcSignalHit class

Follow SRC model and make a scintillator plane class.