GEANT321/erdecks/ertrnt.F

   1 *
   2 * $Id$
   3 *
   4 * $Log$
   5 * Revision 1.1.1.1  1996/03/06 15:37:35  mclareni
   6 * Add geane321 source directories
   7 *
   8 *
   9 #include "geant321/pilot.h"
  10 *CMZ :  3.21/02 29/03/94  15.41.49  by  S.Giani
  11 *-- Author :
  12       SUBROUTINE ERTRNT
  13 C.
  14 C.    ******************************************************************
  15 C.    *                                                                *
  16 C.    *    Average neutral track is extrapolated by one step           *
  17 C.    *                                                                *
  18 C.    *    ==>Called by : ERTRGO                                       *
  19 C.    *       Original routine : GTNINO                                *
  20 C.    *       Authors   M.Maire, E.Nagy  *********                     *
  21 C.    *                                                                *
  22 C.    ******************************************************************
  23 C.
  24 #include "geant321/ertrio.inc"
  25 #include "geant321/gconst.inc"
  26 #include "geant321/gctmed.inc"
  27 #include "geant321/gctrak.inc"
  28 *
  29 * *** Compute point where to store error matrix
  30 *
  31       STEPER = BIG
  32       DO 20 IPR = 1,NEPRED
  33          STEPE  = BIG
  34          IF (LELENG) STEPE = ERLENG(IPR) - SLENG
  35          IF (LEPLAN) THEN
  36             SCAL1 = 0.
  37             SCAL2 = 0.
  38             DO 18 I=1,3
  39                SCAL1 = SCAL1 + ERPLO(I,4,IPR)*(ERPLO(I,3,IPR)-VECT(I))
  40                SCAL2 = SCAL2 + ERPLO(I,4,IPR)*VECT(I+3)
  41    18       CONTINUE
  42             STEPE = SCAL1/SCAL2
  43          ENDIF
  44          IF (STEPE.LE.PREC) STEPE = BIG
  45          IF (STEPE.LT.STEPER) THEN
  46             STEPER = STEPE
  47             INLIST = IPR
  48          ENDIF
  49    20 CONTINUE
  50 *
  51       STEP = BIG
  52       CALL GTNEXT
  53 *
  54       IF(STEPER.LT.SNEXT) THEN
  55          STEP = STEPER
  56          INWVOL = 0
  57          IMEC   = 27
  58          NMEC   = NMEC + 1
  59          LMEC(NMEC) = IMEC
  60       ELSE
  61          STEP = SNEXT + PREC
  62          INWVOL = 2
  63          IMEC   = 1
  64          NMEC   = NMEC + 1
  65          LMEC(NMEC) = IMEC
  66          IF ((STEPER-SNEXT).LE.(2*PREC)) THEN
  67             IMEC   = 27
  68             NMEC   = NMEC + 1
  69             LMEC(NMEC) = IMEC
  70          ENDIF
  71       ENDIF
  72 *
  73 * *** Linear transport
  74 *
  75       DO 25 I=1,3
  76          VECT(I) = VECT(I) + STEP*VECT(I+3)
  77    25 CONTINUE
  78 *
  79       SLENG = SLENG + STEP
  80 *
  81 * *** Propagate error matrix
  82 *
  83       IF (.NOT. LEONLY) CALL ERPROP
  84 *
  85 * *** Store informations
  86 *
  87       IF(IMEC.EQ.27) CALL ERSTOR
  88 *
  89       END