00001 /* zlarnd.f -- translated by f2c (version 20061008). 00002 You must link the resulting object file with libf2c: 00003 on Microsoft Windows system, link with libf2c.lib; 00004 on Linux or Unix systems, link with .../path/to/libf2c.a -lm 00005 or, if you install libf2c.a in a standard place, with -lf2c -lm 00006 -- in that order, at the end of the command line, as in 00007 cc *.o -lf2c -lm 00008 Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., 00009 00010 http://www.netlib.org/f2c/libf2c.zip 00011 */ 00012 00013 #include "f2c.h" 00014 #include "blaswrap.h" 00015 00016 /* Double Complex */ VOID zlarnd_(doublecomplex * ret_val, integer *idist, 00017 integer *iseed) 00018 { 00019 /* System generated locals */ 00020 doublereal d__1, d__2; 00021 doublecomplex z__1, z__2, z__3; 00022 00023 /* Builtin functions */ 00024 double log(doublereal), sqrt(doublereal); 00025 void z_exp(doublecomplex *, doublecomplex *); 00026 00027 /* Local variables */ 00028 doublereal t1, t2; 00029 extern doublereal dlaran_(integer *); 00030 00031 00032 /* -- LAPACK auxiliary routine (version 3.1) -- */ 00033 /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ 00034 /* November 2006 */ 00035 00036 /* .. Scalar Arguments .. */ 00037 /* .. */ 00038 /* .. Array Arguments .. */ 00039 /* .. */ 00040 00041 /* Purpose */ 00042 /* ======= */ 00043 00044 /* ZLARND returns a random complex number from a uniform or normal */ 00045 /* distribution. */ 00046 00047 /* Arguments */ 00048 /* ========= */ 00049 00050 /* IDIST (input) INTEGER */ 00051 /* Specifies the distribution of the random numbers: */ 00052 /* = 1: real and imaginary parts each uniform (0,1) */ 00053 /* = 2: real and imaginary parts each uniform (-1,1) */ 00054 /* = 3: real and imaginary parts each normal (0,1) */ 00055 /* = 4: uniformly distributed on the disc abs(z) <= 1 */ 00056 /* = 5: uniformly distributed on the circle abs(z) = 1 */ 00057 00058 /* ISEED (input/output) INTEGER array, dimension (4) */ 00059 /* On entry, the seed of the random number generator; the array */ 00060 /* elements must be between 0 and 4095, and ISEED(4) must be */ 00061 /* odd. */ 00062 /* On exit, the seed is updated. */ 00063 00064 /* Further Details */ 00065 /* =============== */ 00066 00067 /* This routine calls the auxiliary routine DLARAN to generate a random */ 00068 /* real number from a uniform (0,1) distribution. The Box-Muller method */ 00069 /* is used to transform numbers from a uniform to a normal distribution. */ 00070 00071 /* ===================================================================== */ 00072 00073 /* .. Parameters .. */ 00074 /* .. */ 00075 /* .. Local Scalars .. */ 00076 /* .. */ 00077 /* .. External Functions .. */ 00078 /* .. */ 00079 /* .. Intrinsic Functions .. */ 00080 /* .. */ 00081 /* .. Executable Statements .. */ 00082 00083 /* Generate a pair of real random numbers from a uniform (0,1) */ 00084 /* distribution */ 00085 00086 /* Parameter adjustments */ 00087 --iseed; 00088 00089 /* Function Body */ 00090 t1 = dlaran_(&iseed[1]); 00091 t2 = dlaran_(&iseed[1]); 00092 00093 if (*idist == 1) { 00094 00095 /* real and imaginary parts each uniform (0,1) */ 00096 00097 z__1.r = t1, z__1.i = t2; 00098 ret_val->r = z__1.r, ret_val->i = z__1.i; 00099 } else if (*idist == 2) { 00100 00101 /* real and imaginary parts each uniform (-1,1) */ 00102 00103 d__1 = t1 * 2. - 1.; 00104 d__2 = t2 * 2. - 1.; 00105 z__1.r = d__1, z__1.i = d__2; 00106 ret_val->r = z__1.r, ret_val->i = z__1.i; 00107 } else if (*idist == 3) { 00108 00109 /* real and imaginary parts each normal (0,1) */ 00110 00111 d__1 = sqrt(log(t1) * -2.); 00112 d__2 = t2 * 6.2831853071795864769252867663; 00113 z__3.r = 0., z__3.i = d__2; 00114 z_exp(&z__2, &z__3); 00115 z__1.r = d__1 * z__2.r, z__1.i = d__1 * z__2.i; 00116 ret_val->r = z__1.r, ret_val->i = z__1.i; 00117 } else if (*idist == 4) { 00118 00119 /* uniform distribution on the unit disc abs(z) <= 1 */ 00120 00121 d__1 = sqrt(t1); 00122 d__2 = t2 * 6.2831853071795864769252867663; 00123 z__3.r = 0., z__3.i = d__2; 00124 z_exp(&z__2, &z__3); 00125 z__1.r = d__1 * z__2.r, z__1.i = d__1 * z__2.i; 00126 ret_val->r = z__1.r, ret_val->i = z__1.i; 00127 } else if (*idist == 5) { 00128 00129 /* uniform distribution on the unit circle abs(z) = 1 */ 00130 00131 d__1 = t2 * 6.2831853071795864769252867663; 00132 z__2.r = 0., z__2.i = d__1; 00133 z_exp(&z__1, &z__2); 00134 ret_val->r = z__1.r, ret_val->i = z__1.i; 00135 } 00136 return ; 00137 00138 /* End of ZLARND */ 00139 00140 } /* zlarnd_ */