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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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| subroutine dlaruv | ( | integer, dimension( 4 ) | ISEED, |
| integer | N, | ||
| double precision, dimension( n ) | X | ||
| ) |
DLARUV returns a vector of n random real numbers from a uniform distribution.
Download DLARUV + dependencies [TGZ] [ZIP] [TXT]
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.
| [in,out] | ISEED | ISEED is 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. |
| [in] | N | N is INTEGER
The number of random numbers to be generated. N <= 128. |
| [out] | X | X is DOUBLE PRECISION array, dimension (N)
The generated random numbers. |
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.