source: PSPA/parmelaPSPA/trunk/rn32.f @ 405

      FUNCTION RN32(IDUMMY)
C         MACHINE-INDEPENDENT RANDOM NUMBER GENERATOR
C         PRODUCES UNIFORMLY-DISTRIBUTED FLOATING-PT.
C               NUMBERS BETWEEN ZERO AND ONE.
C         IDENTICAL SEQUENCE ON ALL MACHINES OF .GE. 32 BITS.
C              UNIVERSAL VERSION,  F.JAMES, 1985
C              IY     IS THE SEED,
C              CONS   IS 2**-31
C              MASK31 IS 17777777777 OCTAL
      PARAMETER (CONS=4.6566128730774E-10, MASK31=2147483647)
      SAVE IY
      DATA IY/65539/
      IY = IY * 69069
C         KEEP ONLY LOWER 31 BITS
      IY = IAND (IY, MASK31)
C         SET LOWER 8 BITS TO ZERO TO ASSURE EXACT FLOAT
      JY = IY /256 *256
      RN32 = CONS*JY
      RETURN
C         ENTRY TO INPUT SEED
      ENTRY RN32IN (IDUMMY)
      IY = IDUMMY
      RETURN
C         ENTRY TO OUTPUT SEED
      ENTRY RN32OT (IDUMMY)
cbm 27/07/00      IDUMMY = IY
      IY = IDUMMY
      RETURN
      END