GEANT321/ghits/gcderr.F

   1 *
   2 * $Id$
   3 *
   4 * $Log$
   5 * Revision 1.1.1.1  1995/10/24 10:21:08  cernlib
   6 * Geant
   7 *
   8 *
   9 #include "geant321/pilot.h"
  10 *CMZ :  3.21/02 29/03/94  15.41.20  by  S.Giani
  11 *-- Author :
  12       SUBROUTINE GCDERR (ICD,ERP,ERS)
  13 C.
  14 C.    ******************************************************************
  15 C.    *                                                                *
  16 C.    *       ROUTINE TO CALCULATE THE ERROR ON THE CURRENT DIVISION   *
  17 C.    *       INFORMATION AS OBTAINED BY "GCDRIF"                      *
  18 C.    *                                                                *
  19 C.    *       INPUT:  ICD = DIGITIZED CURRENT DIVISION INFORMATION     *
  20 C.    *                     ( 0 ... 1000 )                             *
  21 C.    *               ERP = VARIANCE OF GAUSSIAN DISTRIBUTED PEDESTAL  *
  22 C.    *                     ERRORS ON THE MEASURED PULSE HEIGHTS       *
  23 C.    *                     RELATIVE TO THE SUM OF THE PULSE HEIGHTS   *
  24 C.    *               ERS = VARIANCE OF GAUSSIAN DISTRIBUTED SLOPE     *
  25 C.    *                     ERRORS ON THE MEASURED PULSE HEIGHTS       *
  26 C.    *                     RELATIVE TO EACH PULSE HEIGHT              *
  27 C.    *       OUTPUT: ICD = VALUE UPDATED ACCORDING TO RANDOM ERRORS   *
  28 C.    *                                                                *
  29 C.    *    ==>Called by : <USER>, GUDIGI                               *
  30 C.    *       Author    D.Mitaroff  *********                          *
  31 C.    *                                                                *
  32 C.    ******************************************************************
  33 C.
  34       COMMON  /GCYDR/ ZL
  35       DIMENSION RNDM(4)
  36 C
  37       Z = ICD
  38 C
  39 C---- CALCULATE PEDESTAL ERRORS FOR VARIANCE BEING 1.
  40       CALL GRNDM(RNDM,4)
  41 *          call rannor(eps1,eps2)
  42       RY=RNDM(1)
  43       RZ=RNDM(2)
  44       RX=6.283185*RZ
  45       A1=SQRT(-2.*LOG(RY))
  46       EPS1=A1*SIN(RX)
  47       EPS2=A1*COS(RX)
  48       DZP = - EPS1 * Z + EPS2 * (ZL - Z)
  49 C
  50 C---- CALCULATE SLOPE ERRORS FOR VARIANCE BEING 1.
  51 *          call rannor(eps1,eps2)
  52       RY=RNDM(3)
  53       RZ=RNDM(4)
  54       RX=6.283185*RZ
  55       A1=SQRT(-2.*LOG(RY))
  56       EPS1=A1*SIN(RX)
  57       EPS2=A1*COS(RX)
  58       DZS = (EPS2 - EPS1) * Z * (ZL - Z) / ZL
  59 C
  60 C---- CALCULATE NEW VALUE OF ICD FOR VARIANCES ERP, ERS.
  61       Z = Z + ERP * DZP + ERS * DZS
  62       IF (Z .LT. 0.)   Z = 0.
  63       IF (Z .GT. ZL)   Z = ZL
  64 C
  65       ICD = Z
  66 C
  67       END