/*  -- translated by f2c (version 19940927).

   You must link the resulting object file with the libraries:

	-lf2c -lm   (in that order)

*/

#include "f2c.h"

doublereal dlaran_(integer *iseed)

{

    /* System generated locals */

    doublereal ret_val;

    /* Local variables */

    static integer it1, it2, it3, it4;

/*  -- LAPACK auxiliary routine (version 2.0) --   

       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   

       Courant Institute, Argonne National Lab, and Rice University   

       February 29, 1992   

    Purpose   

    =======   

    DLARAN returns a random real number from a uniform (0,1)   

    distribution.   

    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.   

    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.   

    ===================================================================== 

       multiply the seed by the multiplier modulo 2**48   

       Parameter adjustments */

    --iseed;

    /* Function Body */

    it4 = iseed[4] * 2549;

    it3 = it4 / 4096;

    it4 -= it3 << 12;

    it3 = it3 + iseed[3] * 2549 + iseed[4] * 2508;

    it2 = it3 / 4096;

    it3 -= it2 << 12;

    it2 = it2 + iseed[2] * 2549 + iseed[3] * 2508 + iseed[4] * 322;

    it1 = it2 / 4096;

    it2 -= it1 << 12;

    it1 = it1 + iseed[1] * 2549 + iseed[2] * 2508 + iseed[3] * 322 + iseed[4] 

	    * 494;

    it1 %= 4096;

/*     return updated seed */

    iseed[1] = it1;

    iseed[2] = it2;

    iseed[3] = it3;

    iseed[4] = it4;

/*     convert 48-bit integer to a real number in the interval (0,1) */

    ret_val = ((doublereal) it1 + ((doublereal) it2 + ((doublereal) it3 + (

	    doublereal) it4 * 2.44140625e-4) * 2.44140625e-4) * 2.44140625e-4)

	     * 2.44140625e-4;

    return ret_val;

/*     End of DLARAN */

} /* dlaran_ */