/** ======================================================================* NIST Guide to Available Math Software.* Fullsource for module SSYEVX.C from package CLAPACK.* Retrieved from NETLIB on Fri Mar 10 14:23:44 2000.* ======================================================================*/#include <f2c.h>/* Subroutine */ int slarnv_(integer *idist, integer *iseed, integer *n, real 	*x){/*  -- LAPACK auxiliary routine (version 2.0) --          Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,          Courant Institute, Argonne National Lab, and Rice University          September 30, 1994       Purpose       =======       SLARNV returns a vector of n random real numbers from a uniform or       normal distribution.       Arguments       =========       IDIST   (input) INTEGER               Specifies the distribution of the random numbers:               = 1:  uniform (0,1)               = 2:  uniform (-1,1)               = 3:  normal (0,1)       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.       X       (output) REAL array, dimension (N)               The generated random numbers.       Further Details       ===============       This routine calls the auxiliary routine SLARUV to generate random       real numbers from a uniform (0,1) distribution, in batches of up to       128 using vectorisable code. The Box-Muller method is used to       transform numbers from a uniform to a normal distribution.       =====================================================================          Parameter adjustments          Function Body */    /* System generated locals */    integer i__1, i__2, i__3;    /* Builtin functions */    double log(doublereal), sqrt(doublereal), cos(doublereal);    /* Local variables */    static integer i;    static real u[128];    static integer il, iv, il2;    extern /* Subroutine */ int slaruv_(integer *, integer *, real *);#define X(I) x[(I)-1]#define ISEED(I) iseed[(I)-1]    i__1 = *n;    for (iv = 1; iv <= *n; iv += 64) {/* Computing MIN */	i__2 = 64, i__3 = *n - iv + 1;	il = min(i__2,i__3);	if (*idist == 3) {	    il2 = il << 1;	} else {	    il2 = il;	}/*        Call SLARUV to generate IL2 numbers from a uniform (0,1)             distribution (IL2 <= LV) */	slaruv_(&ISEED(1), &il2, u);	if (*idist == 1) {/*           Copy generated numbers */	    i__2 = il;	    for (i = 1; i <= il; ++i) {		X(iv + i - 1) = u[i - 1];/* L10: */	    }	} else if (*idist == 2) {/*           Convert generated numbers to uniform (-1,1) distribution */	    i__2 = il;	    for (i = 1; i <= il; ++i) {		X(iv + i - 1) = u[i - 1] * 2.f - 1.f;/* L20: */	    }	} else if (*idist == 3) {/*           Convert generated numbers to normal (0,1) distribution */	    i__2 = il;	    for (i = 1; i <= il; ++i) {		X(iv + i - 1) = sqrt(log(u[(i << 1) - 2]) * -2.f) * cos(u[(i 			<< 1) - 1] * 6.2831853071795864769252867663f);/* L30: */	    }	}/* L40: */    }    return 0;/*     End of SLARNV */} /* slarnv_ */