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+ REAL FUNCTION sla_RANDOM (SEED)
+*+
+* - - - - - - -
+* R A N D O M
+* - - - - - - -
+*
+* Generate pseudo-random real number in the range 0 <= X < 1.
+* (single precision)
+*
+* !!! Version for VAX/VMS and DECstation !!!
+*
+* Given:
+* SEED real an arbitrary real number
+*
+* Notes:
+*
+* 1) The result is a pseudo-random REAL number in the range
+* 0 <= sla_RANDOM < 1.
+*
+* 2) SEED is used first time through only.
+*
+* Called: RAN (a REAL function from the DEC Fortran Library)
+*
+* P.T.Wallace Starlink 14 October 1991
+*-
+
+ IMPLICIT NONE
+
+ REAL SEED
+
+ REAL RAN
+
+ REAL AS
+ INTEGER ISEED
+ LOGICAL FIRST
+ SAVE FIRST
+ DATA FIRST /.TRUE./
+
+
+
+* If first time, turn SEED into a large, odd integer
+ IF (FIRST) THEN
+ AS=ABS(SEED)+1.0
+ ISEED=NINT(AS/10.0**(NINT(ALOG10(AS))-6))
+ IF (MOD(ISEED,2).EQ.0) ISEED=ISEED+1
+ FIRST=.FALSE.
+ END IF
+
+* Next pseudo-random number
+ sla_RANDOM=RAN(ISEED)
+
+ END