class HRichDigitizer: public HReconstructor

 At the end of the execute() the TClonesArray that contains
 the track numbers is sorted by the pad addreses. Then
 every CalSim object is retrieved from the catRichCal
 container to assign to each pad the corresponding nTrack1, nTrack2.
 These 2 numbers are the indexes of the track nbs. in the TClonesArray
 HRichTrack. Finally the noise is calculated.

 this function calculates the charge on each wire and saves it in a TList
 moreover, it saves the track number and the corresponding flag
 (cf HRichTrack) in a second TList.
 The charge is calculated according to one exponential function
 obtained fitting the total charge distribution of the photon candidates
 belonging to class one ( OEM data).
 That means that the so calculated charge isn't in reality the
 original charge deposited on the wire but the total amount of the charge
 coupled to the pads. Therefore it isn't any longer necessary to
 use an additional coupling factor. ( 75%)

 for every photon hit on a pad the resulting charge on a wire
 is calculated and the track number of the photon parent is stored.
 (cf. calcChargeOnWire).

 We assume that the feed back photon is produced on the anodic wire,
 the number of the feed back photon is proportional to the value A0.

 for every direct hit (charge particle hitting the RICH or ionizing
 the gas near the surface of the photon detector)  the
 resulting charge on the wires is calculated and the track number
 of the charged particle hitting the pad is stored.
 (cf. calcChargeOnWire)

 check what you want to translate - probably real corners

 nbNoisePads is the number of pads on which the electronic noise
 will produce a non zero signal. This number is extimated taken
 into account the threshold taht has been used for the pedestals.

 the charge induced on the pad by the electronic noise
 is calculated according to a gauss function with
 sigma = fSigmaPad*fIncreaseNoise and mean 0.
 Anyway only values above threshold
 (fSigmaValue * fSigmaPad)
 are drawn

 An additional charge is added on pads that have already
 been "fired" by a photon.
 This charge is drawn according to a Gauss distribution
 with sigma = fSigmaPad*fIncreaseNoise and mean = 0.

 this function checks if the pads fired by the photons
 are above threshold.
 The procedure used to calculate the threshols is the
 same used for real data.  The charge on the pad is composed
 of the signal induced by the photon plus the noise fluctuation.
 The float part of the mean value of the noise distribution
 is added to the charge then
 the charge value is casted to an integer and is
 compared to the threshold.
 If the charge is above threshold, the float part of the mean is
 subtracted from the total charge and a random number between 0 and 1
 is added to the integer produce a float.

 for each wire on which some charge has been deposited
 the corresponding coupled pads are calculated.
 The function updateCharge creates a HRichCalSim obj if
 the charge on the pad is greater than zero.
 A cut off threshold is applied to each pad in the execute func.
 after the digitilasation of all the hits.
 If the pad is hit twice in the same event, the charges
 corresponding to the 2 different hits are added.
 The particle track number is passed to the function
 updateCharge, too.

 iWireNr is used to determine whether the wire is
 the left or the right one.
 Even wire numbers correspond to right.
 for the side pads a coupling costant is multiplied
 by the charge on the central pad, the upper an lower
 pad get an amount of charge that is position dependent.

 This function calculate the charge ratio between the upper/lower
 pad and the central one

 This function calculate the charge induced on the central pad.
 the coupling factor (75%) from the wire to the pad has
 been discarded since the charge distribution on the wire
 has been calculated fitting pads responses.

 This function creates an HRichCalSim obj that corresponds
 to a fired pad, it calls the function updateTrack,
 that stores the corresponding track numbers.

 this function stores the track numbers of parent
 particles of photons and of direct hits in a linear
 category (HRichTrack). This category is set sortable.