HIJING/hipyset1_35/rlu_hijing.F

   1 * $Id$
   2
   3 C*********************************************************************
   4
   5       FUNCTION RLU_HIJING(IDUM)
   6
   7 C...Purpose: to generate random numbers uniformly distributed between
   8 C...0 and 1, excluding the endpoints.
   9 #include "ludatr_hijing.inc"
  10       EQUIVALENCE (MRLU1,MRLU(1)),(MRLU2,MRLU(2)),(MRLU3,MRLU(3)),
  11      &(MRLU4,MRLU(4)),(MRLU5,MRLU(5)),(MRLU6,MRLU(6)),
  12      &(RRLU98,RRLU(98)),(RRLU99,RRLU(99)),(RRLU00,RRLU(100))
  13
  14 C...Initialize generation from given seed.
  15       IF(MRLU2.EQ.0) THEN
  16         IJ=MOD(MRLU1/30082,31329)
  17         KL=MOD(MRLU1,30082)
  18         I=MOD(IJ/177,177)+2
  19         J=MOD(IJ,177)+2
  20         K=MOD(KL/169,178)+1
  21         L=MOD(KL,169)
  22         DO 110 II=1,97
  23         S=0.
  24         T=0.5
  25         DO 100 JJ=1,24
  26         M=MOD(MOD(I*J,179)*K,179)
  27         I=J
  28         J=K
  29         K=M
  30         L=MOD(53*L+1,169)
  31         IF(MOD(L*M,64).GE.32) S=S+T
  32   100   T=0.5*T
  33   110   RRLU(II)=S
  34         TWOM24=1.
  35         DO 120 I24=1,24
  36   120   TWOM24=0.5*TWOM24
  37         RRLU98=362436.*TWOM24
  38         RRLU99=7654321.*TWOM24
  39         RRLU00=16777213.*TWOM24
  40         MRLU2=1
  41         MRLU3=0
  42         MRLU4=97
  43         MRLU5=33
  44       ENDIF
  45
  46 C...Generate next random number.
  47   130 RUNI=RRLU(MRLU4)-RRLU(MRLU5)
  48       IF(RUNI.LT.0.) RUNI=RUNI+1.
  49       RRLU(MRLU4)=RUNI
  50       MRLU4=MRLU4-1
  51       IF(MRLU4.EQ.0) MRLU4=97
  52       MRLU5=MRLU5-1
  53       IF(MRLU5.EQ.0) MRLU5=97
  54       RRLU98=RRLU98-RRLU99
  55       IF(RRLU98.LT.0.) RRLU98=RRLU98+RRLU00
  56       RUNI=RUNI-RRLU98
  57       IF(RUNI.LT.0.) RUNI=RUNI+1.
  58       IF(RUNI.LE.0.OR.RUNI.GE.1.) GOTO 130
  59
  60 C...Update counters. Random number to output.
  61       MRLU3=MRLU3+1
  62       IF(MRLU3.EQ.1000000000) THEN
  63         MRLU2=MRLU2+1
  64         MRLU3=0
  65       ENDIF
  66       RLU_HIJING=RUNI
  67
  68       RETURN
  69       END