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dlaruv

 NAME
      DLARUV - return a vector of n random real numbers from a
      uniform (0,1)

 SYNOPSIS
      SUBROUTINE DLARUV( ISEED, N, X )

          INTEGER        N

          INTEGER        ISEED( 4 )

          DOUBLE         PRECISION X( N )

 PURPOSE
      DLARUV returns a vector of n random real numbers from a uni-
      form (0,1) distribution (n <= 128).

      This is an auxiliary routine called by DLARNV and ZLARNV.

 ARGUMENTS
      ISEED   (input/output) INTEGER array, dimension (4)
              On entry, the seed of the random number generator;
              the array elements must be between 0 and 4095, and
              ISEED(4) must be odd.  On exit, the seed is updated.

      N       (input) INTEGER
              The number of random numbers to be generated. N <=
              128.

      X       (output) DOUBLE PRECISION array, dimension (N)
              The generated random numbers.

 FURTHER DETAILS
      This routine uses a multiplicative congruential method with
      modulus 2**48 and multiplier 33952834046453 (see G. S. Fish-
      man,
      `Multiplicative congruential random number generators with
      modulus 2**b: an exhaustive analysis for b = 32 and a par-
      tial analysis for b = 48', Math. Comp. 189, pp 331-344,
      1990).

      48-bit integers are stored in 4 integer array elements with
      12 bits per element. Hence the routine is portable across
      machines with integers of 32 bits or more.