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      SUBROUTINE DLARUV( ISEED, N, X )
*
*  -- LAPACK auxiliary routine (version 3.2) --
*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*     November 2006
*
*     .. Scalar Arguments ..
      INTEGER            N
*     ..
*     .. Array Arguments ..
      INTEGER            ISEED( 4 )
      DOUBLE PRECISION   X( N )
*     ..
*
*  Purpose
*  =======
*
*  DLARUV returns a vector of n random real numbers from a uniform (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.Fishman,
*  'Multiplicative congruential random number generators with modulus
*  2**b: an exhaustive analysis for b = 32 and a partial 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.
*
*  =====================================================================
*
*     .. Parameters ..
      DOUBLE PRECISION   ONE
      PARAMETER          ( ONE = 1.0D0 )
      INTEGER            LV, IPW2
      DOUBLE PRECISION   R
      PARAMETER          ( LV = 128, IPW2 = 4096, R = ONE / IPW2 )
*     ..
*     .. Local Scalars ..
      INTEGER            I, I1, I2, I3, I4, IT1, IT2, IT3, IT4, J
*     ..
*     .. Local Arrays ..
      INTEGER            MM( LV, 4 )
*     ..
*     .. Intrinsic Functions ..
      INTRINSIC          DBLEMINMOD
*     ..
*     .. Data statements ..
      DATA               ( MM( 1, J ), J = 14 ) / 4943222508,
     $                   2549 /
      DATA               ( MM( 2, J ), J = 14 ) / 26377893754,
     $                   1145 /
      DATA               ( MM( 3, J ), J = 14 ) / 25514401766,
     $                   2253 /
      DATA               ( MM( 4, J ), J = 14 ) / 20087523572,
     $                   305 /
      DATA               ( MM( 5, J ), J = 14 ) / 125328592893,
     $                   3301 /
      DATA               ( MM( 6, J ), J = 14 ) / 3344123307,
     $                   1065 /
      DATA               ( MM( 7, J ), J = 14 ) / 408418481297,
     $                   3133 /
      DATA               ( MM( 8, J ), J = 14 ) / 17396433966,
     $                   2913 /
      DATA               ( MM( 9, J ), J = 14 ) / 31432405758,
     $                   3285 /
      DATA               ( MM( 10, J ), J = 14 ) / 346826382598,
     $                   1241 /
      DATA               ( MM( 11, J ), J = 14 ) / 68823443406,
     $                   1197 /
      DATA               ( MM( 12, J ), J = 14 ) / 1657462922,
     $                   3729 /
      DATA               ( MM( 13, J ), J = 14 ) / 123838141038,
     $                   2501 /
      DATA               ( MM( 14, J ), J = 14 ) / 31669132934,
     $                   1673 /
      DATA               ( MM( 15, J ), J = 14 ) / 129236492091,
     $                   541 /
      DATA               ( MM( 16, J ), J = 14 ) / 34223392451,
     $                   2753 /
      DATA               ( MM( 17, J ), J = 14 ) / 127038081580,
     $                   949 /
      DATA               ( MM( 18, J ), J = 14 ) / 20168221958,
     $                   2361 /
      DATA               ( MM( 19, J ), J = 14 ) / 15428322055,
     $                   1165 /
      DATA               ( MM( 20, J ), J = 14 ) / 286230781507,
     $                   4081 /
      DATA               ( MM( 21, J ), J = 14 ) / 69736331078,
     $                   2725 /
      DATA               ( MM( 22, J ), J = 14 ) / 170629703273,
     $                   3305 /
      DATA               ( MM( 23, J ), J = 14 ) / 49163717,
     $                   3069 /
      DATA               ( MM( 24, J ), J = 14 ) / 9312249854,
     $                   3617 /
      DATA               ( MM( 25, J ), J = 14 ) / 144420812916,
     $                   3733 /
      DATA               ( MM( 26, J ), J = 14 ) / 44440193971,
     $                   409 /
      DATA               ( MM( 27, J ), J = 14 ) / 357714782889,
     $                   2157 /
      DATA               ( MM( 28, J ), J = 14 ) / 39442423831,
     $                   1361 /
      DATA               ( MM( 29, J ), J = 14 ) / 21844812621,
     $                   3973 /
      DATA               ( MM( 30, J ), J = 14 ) / 166120751541,
     $                   1865 /
      DATA               ( MM( 31, J ), J = 14 ) / 34824058893,
     $                   2525 /
      DATA               ( MM( 32, J ), J = 14 ) / 657622736,
     $                   1409 /
      DATA               ( MM( 33, J ), J = 14 ) / 302333763992,
     $                   3445 /
      DATA               ( MM( 34, J ), J = 14 ) / 3618812787,
     $                   3577 /
      DATA               ( MM( 35, J ), J = 14 ) / 12672342125,
     $                   77 /
      DATA               ( MM( 36, J ), J = 14 ) / 18286412364,
     $                   3761 /
      DATA               ( MM( 37, J ), J = 14 ) / 16440052460,
     $                   2149 /
      DATA               ( MM( 38, J ), J = 14 ) / 37981122257,
     $                   1449 /
      DATA               ( MM( 39, J ), J = 14 ) / 308731351574,
     $                   3005 /
      DATA               ( MM( 40, J ), J = 14 ) / 240026403912,
     $                   225 /
      DATA               ( MM( 41, J ), J = 14 ) / 287023021216,
     $                   85 /
      DATA               ( MM( 42, J ), J = 14 ) / 3876403248,
     $                   3673 /
      DATA               ( MM( 43, J ), J = 14 ) / 190518323401,
     $                   3117 /
      DATA               ( MM( 44, J ), J = 14 ) / 159322472124,
     $                   3089 /
      DATA               ( MM( 45, J ), J = 14 ) / 179720342762,
     $                   1349 /
      DATA               ( MM( 46, J ), J = 14 ) / 12342637149,
     $                   2057 /
      DATA               ( MM( 47, J ), J = 14 ) / 346012872245,
     $                   413 /
      DATA               ( MM( 48, J ), J = 14 ) / 3281691166,
     $                   65 /
      DATA               ( MM( 49, J ), J = 14 ) / 2861496466,
     $                   1845 /
      DATA               ( MM( 50, J ), J = 14 ) / 195015974018,
     $                   697 /
      DATA               ( MM( 51, J ), J = 14 ) / 61723941399,
     $                   3085 /
      DATA               ( MM( 52, J ), J = 14 ) / 20702584190,
     $                   3441 /
      DATA               ( MM( 53, J ), J = 14 ) / 333118432879,
     $                   1573 /
      DATA               ( MM( 54, J ), J = 14 ) / 769336153,
     $                   3689 /
      DATA               ( MM( 55, J ), J = 14 ) / 155814722320,
     $                   2941 /
      DATA               ( MM( 56, J ), J = 14 ) / 2412240718,
     $                   929 /
      DATA               ( MM( 57, J ), J = 14 ) / 2800433712,
     $                   533 /
      DATA               ( MM( 58, J ), J = 14 ) / 18920962159,
     $                   2841 /
      DATA               ( MM( 59, J ), J = 14 ) / 28717612318,
     $                   4077 /
      DATA               ( MM( 60, J ), J = 14 ) / 204528102091,
     $                   721 /
      DATA               ( MM( 61, J ), J = 14 ) / 12275663443,
     $                   2821 /
      DATA               ( MM( 62, J ), J = 14 ) / 28384421510,
     $                   2249 /
      DATA               ( MM( 63, J ), J = 14 ) / 20941449,
     $                   2397 /
      DATA               ( MM( 64, J ), J = 14 ) / 277012381956,
     $                   2817 /
      DATA               ( MM( 65, J ), J = 14 ) / 365410862201,
     $                   245 /
      DATA               ( MM( 66, J ), J = 14 ) / 39936033137,
     $                   1913 /
      DATA               ( MM( 67, J ), J = 14 ) / 1928403399,
     $                   1997 /
      DATA               ( MM( 68, J ), J = 14 ) / 225331681321,
     $                   3121 /
      DATA               ( MM( 69, J ), J = 14 ) / 349114992271,
     $                   997 /
      DATA               ( MM( 70, J ), J = 14 ) / 288910843667,
     $                   1833 /
      DATA               ( MM( 71, J ), J = 14 ) / 285734382703,
     $                   2877 /
      DATA               ( MM( 72, J ), J = 14 ) / 20942408629,
     $                   1633 /
      DATA               ( MM( 73, J ), J = 14 ) / 181815892365,
     $                   981 /
      DATA               ( MM( 74, J ), J = 14 ) / 68823912431,
     $                   2009 /
      DATA               ( MM( 75, J ), J = 14 ) / 14072881113,
     $                   941 /
      DATA               ( MM( 76, J ), J = 14 ) / 634263922,
     $                   2449 /
      DATA               ( MM( 77, J ), J = 14 ) / 32315122554,
     $                   197 /
      DATA               ( MM( 78, J ), J = 14 ) / 8151456184,
     $                   2441 /
      DATA               ( MM( 79, J ), J = 14 ) / 35241712099,
     $                   285 /
      DATA               ( MM( 80, J ), J = 14 ) / 191416773228,
     $                   1473 /
      DATA               ( MM( 81, J ), J = 14 ) / 51626574012,
     $                   2741 /
      DATA               ( MM( 82, J ), J = 14 ) / 16422701921,
     $                   3129 /
      DATA               ( MM( 83, J ), J = 14 ) / 30325873452,
     $                   909 /
      DATA               ( MM( 84, J ), J = 14 ) / 214429613901,
     $                   2801 /
      DATA               ( MM( 85, J ), J = 14 ) / 34801970572,
     $                   421 /
      DATA               ( MM( 86, J ), J = 14 ) / 11918173309,
     $                   4073 /
      DATA               ( MM( 87, J ), J = 14 ) / 33576763171,
     $                   2813 /
      DATA               ( MM( 88, J ), J = 14 ) / 8371410817,
     $                   2337 /
      DATA               ( MM( 89, J ), J = 14 ) / 282637233039,
     $                   1429 /
      DATA               ( MM( 90, J ), J = 14 ) / 233228031696,
     $                   1177 /
      DATA               ( MM( 91, J ), J = 14 ) / 208931851256,
     $                   1901 /
      DATA               ( MM( 92, J ), J = 14 ) / 37801843715,
     $                   81 /
      DATA               ( MM( 93, J ), J = 14 ) / 17006632077,
     $                   1669 /
      DATA               ( MM( 94, J ), J = 14 ) / 37124993019,
     $                   2633 /
      DATA               ( MM( 95, J ), J = 14 ) / 15037841497,
     $                   2269 /
      DATA               ( MM( 96, J ), J = 14 ) / 200016311101,
     $                   129 /
      DATA               ( MM( 97, J ), J = 14 ) / 33751925717,
     $                   1141 /
      DATA               ( MM( 98, J ), J = 14 ) / 1621391251,
     $                   249 /
      DATA               ( MM( 99, J ), J = 14 ) / 30901398981,
     $                   3917 /
      DATA               ( MM( 100, J ), J = 14 ) / 376513491978,
     $                   2481 /
      DATA               ( MM( 101, J ), J = 14 ) / 114914411813,
     $                   3941 /
      DATA               ( MM( 102, J ), J = 14 ) / 314622243881,
     $                   2217 /
      DATA               ( MM( 103, J ), J = 14 ) / 33241176,
     $                   2749 /
      DATA               ( MM( 104, J ), J = 14 ) / 308219073846,
     $                   3041 /
      DATA               ( MM( 105, J ), J = 14 ) / 274131923694,
     $                   1877 /
      DATA               ( MM( 106, J ), J = 14 ) / 35927861682,
     $                   345 /
      DATA               ( MM( 107, J ), J = 14 ) / 3316382124,
     $                   2861 /
      DATA               ( MM( 108, J ), J = 14 ) / 1749371660,
     $                   1809 /
      DATA               ( MM( 109, J ), J = 14 ) / 1857593997,
     $                   3141 /
      DATA               ( MM( 110, J ), J = 14 ) / 27842948479,
     $                   2825 /
      DATA               ( MM( 111, J ), J = 14 ) / 220218621141,
     $                   157 /
      DATA               ( MM( 112, J ), J = 14 ) / 21993802886,
     $                   2881 /
      DATA               ( MM( 113, J ), J = 14 ) / 136424233514,
     $                   3637 /
      DATA               ( MM( 114, J ), J = 14 ) / 124420511301,
     $                   1465 /
      DATA               ( MM( 115, J ), J = 14 ) / 202022953604,
     $                   2829 /
      DATA               ( MM( 116, J ), J = 14 ) / 316013321888,
     $                   2161 /
      DATA               ( MM( 117, J ), J = 14 ) / 278518321836,
     $                   3365 /
      DATA               ( MM( 118, J ), J = 14 ) / 277224051990,
     $                   361 /
      DATA               ( MM( 119, J ), J = 14 ) / 121736382058,
     $                   2685 /
      DATA               ( MM( 120, J ), J = 14 ) / 18223661692,
     $                   3745 /
      DATA               ( MM( 121, J ), J = 14 ) / 12453271194,
     $                   2325 /
      DATA               ( MM( 122, J ), J = 14 ) / 2252366020,
     $                   3609 /
      DATA               ( MM( 123, J ), J = 14 ) / 39047163285,
     $                   3821 /
      DATA               ( MM( 124, J ), J = 14 ) / 277418422046,
     $                   3537 /
      DATA               ( MM( 125, J ), J = 14 ) / 99739872107,
     $                   517 /
      DATA               ( MM( 126, J ), J = 14 ) / 257313683508,
     $                   3017 /
      DATA               ( MM( 127, J ), J = 14 ) / 114818483525,
     $                   2141 /
      DATA               ( MM( 128, J ), J = 14 ) / 54523663801,
     $                   1537 /
*     ..
*     .. Executable Statements ..
*
      I1 = ISEED( 1 )
      I2 = ISEED( 2 )
      I3 = ISEED( 3 )
      I4 = ISEED( 4 )
*
      DO 10 I = 1MIN( N, LV )
*     
  20     CONTINUE
*
*        Multiply the seed by i-th power of the multiplier modulo 2**48
*
         IT4 = I4*MM( I, 4 )
         IT3 = IT4 / IPW2
         IT4 = IT4 - IPW2*IT3
         IT3 = IT3 + I3*MM( I, 4 ) + I4*MM( I, 3 )
         IT2 = IT3 / IPW2
         IT3 = IT3 - IPW2*IT2
         IT2 = IT2 + I2*MM( I, 4 ) + I3*MM( I, 3 ) + I4*MM( I, 2 )
         IT1 = IT2 / IPW2
         IT2 = IT2 - IPW2*IT1
         IT1 = IT1 + I1*MM( I, 4 ) + I2*MM( I, 3 ) + I3*MM( I, 2 ) +
     $         I4*MM( I, 1 )
         IT1 = MOD( IT1, IPW2 )
*
*        Convert 48-bit integer to a real number in the interval (0,1)
*
         X( I ) = R*DBLE( IT1 )+R*DBLE( IT2 )+R*DBLE( IT3 )+R*
     $            DBLE( IT4 ) ) ) )
*
         IF (X( I ).EQ.1.0D0THEN
*           If a real number has n bits of precision, and the first
*           n bits of the 48-bit integer above happen to be all 1 (which
*           will occur about once every 2**n calls), then X( I ) will
*           be rounded to exactly 1.0. 
*           Since X( I ) is not supposed to return exactly 0.0 or 1.0,
*           the statistically correct thing to do in this situation is
*           simply to iterate again.
*           N.B. the case X( I ) = 0.0 should not be possible.  
            I1 = I1 + 2
            I2 = I2 + 2
            I3 = I3 + 2
            I4 = I4 + 2
            GOTO 20
         END IF
*
   10 CONTINUE
*
*     Return final value of seed
*
      ISEED( 1 ) = IT1
      ISEED( 2 ) = IT2
      ISEED( 3 ) = IT3
      ISEED( 4 ) = IT4
      RETURN
*
*     End of DLARUV
*
      END