/* clarnv.f -- translated by f2c (version 20061008).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
#include "blaswrap.h"
/* Subroutine */ int clarnv_(integer *idist, integer *iseed, integer *n,
complex *x)
{
/* System generated locals */
integer i__1, i__2, i__3, i__4, i__5;
real r__1, r__2;
complex q__1, q__2, q__3;
/* Builtin functions */
double log(doublereal), sqrt(doublereal);
void c_exp(complex *, complex *);
/* Local variables */
integer i__;
real u[128];
integer il, iv;
extern /* Subroutine */ int slaruv_(integer *, integer *, real *);
/* -- LAPACK auxiliary routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* CLARNV returns a vector of n random complex numbers from a uniform or */
/* normal distribution. */
/* Arguments */
/* ========= */
/* IDIST (input) INTEGER */
/* Specifies the distribution of the random numbers: */
/* = 1: real and imaginary parts each uniform (0,1) */
/* = 2: real and imaginary parts each uniform (-1,1) */
/* = 3: real and imaginary parts each normal (0,1) */
/* = 4: uniformly distributed on the disc abs(z) < 1 */
/* = 5: uniformly distributed on the circle abs(z) = 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) COMPLEX 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. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--x;
--iseed;
/* Function Body */
i__1 = *n;
for (iv = 1; iv <= i__1; iv += 64) {
/* Computing MIN */
i__2 = 64, i__3 = *n - iv + 1;
il = min(i__2,i__3);
/* Call SLARUV to generate 2*IL real numbers from a uniform (0,1) */
/* distribution (2*IL <= LV) */
i__2 = il << 1;
slaruv_(&iseed[1], &i__2, u);
if (*idist == 1) {
/* Copy generated numbers */
i__2 = il;
for (i__ = 1; i__ <= i__2; ++i__) {
i__3 = iv + i__ - 1;
i__4 = (i__ << 1) - 2;
i__5 = (i__ << 1) - 1;
q__1.r = u[i__4], q__1.i = u[i__5];
x[i__3].r = q__1.r, x[i__3].i = q__1.i;
/* L10: */
}
} else if (*idist == 2) {
/* Convert generated numbers to uniform (-1,1) distribution */
i__2 = il;
for (i__ = 1; i__ <= i__2; ++i__) {
i__3 = iv + i__ - 1;
r__1 = u[(i__ << 1) - 2] * 2.f - 1.f;
r__2 = u[(i__ << 1) - 1] * 2.f - 1.f;
q__1.r = r__1, q__1.i = r__2;
x[i__3].r = q__1.r, x[i__3].i = q__1.i;
/* L20: */
}
} else if (*idist == 3) {
/* Convert generated numbers to normal (0,1) distribution */
i__2 = il;
for (i__ = 1; i__ <= i__2; ++i__) {
i__3 = iv + i__ - 1;
r__1 = sqrt(log(u[(i__ << 1) - 2]) * -2.f);
r__2 = u[(i__ << 1) - 1] * 6.2831853071795864769252867663f;
q__3.r = 0.f, q__3.i = r__2;
c_exp(&q__2, &q__3);
q__1.r = r__1 * q__2.r, q__1.i = r__1 * q__2.i;
x[i__3].r = q__1.r, x[i__3].i = q__1.i;
/* L30: */
}
} else if (*idist == 4) {
/* Convert generated numbers to complex numbers uniformly */
/* distributed on the unit disk */
i__2 = il;
for (i__ = 1; i__ <= i__2; ++i__) {
i__3 = iv + i__ - 1;
r__1 = sqrt(u[(i__ << 1) - 2]);
r__2 = u[(i__ << 1) - 1] * 6.2831853071795864769252867663f;
q__3.r = 0.f, q__3.i = r__2;
c_exp(&q__2, &q__3);
q__1.r = r__1 * q__2.r, q__1.i = r__1 * q__2.i;
x[i__3].r = q__1.r, x[i__3].i = q__1.i;
/* L40: */
}
} else if (*idist == 5) {
/* Convert generated numbers to complex numbers uniformly */
/* distributed on the unit circle */
i__2 = il;
for (i__ = 1; i__ <= i__2; ++i__) {
i__3 = iv + i__ - 1;
r__1 = u[(i__ << 1) - 1] * 6.2831853071795864769252867663f;
q__2.r = 0.f, q__2.i = r__1;
c_exp(&q__1, &q__2);
x[i__3].r = q__1.r, x[i__3].i = q__1.i;
/* L50: */
}
}
/* L60: */
}
return 0;
/* End of CLARNV */
} /* clarnv_ */