#include "f2c.h" #include "blaswrap.h" /* Complex */ VOID clarnd_(complex * ret_val, integer *idist, integer *iseed) { /* System generated locals */ 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 */ real t1, t2; extern doublereal slaran_(integer *); /* -- LAPACK auxiliary routine (version 3.1) -- */ /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ /* November 2006 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* CLARND returns a random complex number 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. */ /* Further Details */ /* =============== */ /* This routine calls the auxiliary routine SLARAN to generate a random */ /* real number from a uniform (0,1) distribution. The Box-Muller method */ /* is used to transform numbers from a uniform to a normal distribution. */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. External Functions .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ /* Generate a pair of real random numbers from a uniform (0,1) */ /* distribution */ /* Parameter adjustments */ --iseed; /* Function Body */ t1 = slaran_(&iseed[1]); t2 = slaran_(&iseed[1]); if (*idist == 1) { /* real and imaginary parts each uniform (0,1) */ q__1.r = t1, q__1.i = t2; ret_val->r = q__1.r, ret_val->i = q__1.i; } else if (*idist == 2) { /* real and imaginary parts each uniform (-1,1) */ r__1 = t1 * 2.f - 1.f; r__2 = t2 * 2.f - 1.f; q__1.r = r__1, q__1.i = r__2; ret_val->r = q__1.r, ret_val->i = q__1.i; } else if (*idist == 3) { /* real and imaginary parts each normal (0,1) */ r__1 = sqrt(log(t1) * -2.f); r__2 = t2 * 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; ret_val->r = q__1.r, ret_val->i = q__1.i; } else if (*idist == 4) { /* uniform distribution on the unit disc abs(z) <= 1 */ r__1 = sqrt(t1); r__2 = t2 * 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; ret_val->r = q__1.r, ret_val->i = q__1.i; } else if (*idist == 5) { /* uniform distribution on the unit circle abs(z) = 1 */ r__1 = t2 * 6.2831853071795864769252867663f; q__2.r = 0.f, q__2.i = r__1; c_exp(&q__1, &q__2); ret_val->r = q__1.r, ret_val->i = q__1.i; } return ; /* End of CLARND */ } /* clarnd_ */