1 #ifdef HAVE_STDLIB_H
2 #include <stdlib.h>
3 #endif
4 #include <stdio.h>
5 #include <math.h>
6 #include <errno.h>
7 #ifdef sun
8
9 #endif
10 #include "yagi.h"
11
12 extern double boom_factor;
13 #include <errno.h>
14 #define MIN_RDS 0.05 /* Minimum reflector-driven spacing in lambda */
15
randomise(int randomisation_method,double frequency,double max_percent,double ** driven_data,double ** parasitic_data,int driven,int parasites)16 void randomise(int randomisation_method, double frequency, double max_percent, double **driven_data, double**parasitic_data, int driven, int parasites)
17 {
18 int i,elements;
19 static int run_first_time=0;
20 double y, old_boom_length, new_boom_length, a, lambda,**z,l,x,taper;
21 static double max_boom_length;
22 lambda=300/frequency;
23 if(run_first_time==0)
24 {
25 max_boom_length=(1+boom_factor/100)*parasitic_data[parasites][X];
26 }
27 run_first_time++;
28 if ((randomisation_method & DRIVEN_LENGTH) == DRIVEN_LENGTH) /* 1 */
29 {
30 for(i=1;i<=driven; ++i) /* randomise the driven */
31 {
32 y=1+0.02*max_percent*(randreal()-0.5);
33 driven_data[i][LENGTH]*=y;
34 }
35 }
36 if ((randomisation_method & DRIVEN_POSITION) == DRIVEN_POSITION) /* 2 */
37 {
38 for(i=1;i<=driven; ++i) /* randomise the driven position */
39 {
40 y=1+0.02*max_percent*(randreal()-0.5);
41 driven_data[i][X]*=y;
42 }
43 }
44 if ((randomisation_method & REFLECTOR_LENGTH) == REFLECTOR_LENGTH) /* 4 */
45 {
46
47 /* reflector position stays at x=0 */
48 y=1+0.02*max_percent*(randreal()-0.5);
49 parasitic_data[1][LENGTH]*=y;
50 }
51
52 if ((randomisation_method & DIRECTOR_LENGTH) == DIRECTOR_LENGTH) /* 8 */
53 {
54 for(i=2; i<=parasites; ++i)
55 {
56 y=1+0.02*max_percent*(randreal()-0.5);
57 parasitic_data[i][LENGTH]*=y;
58 /* make sure directors dont get longer down the boom */
59 if((parasitic_data[i][LENGTH]>parasitic_data[i-1][LENGTH]) && (i>2))
60 parasitic_data[i][LENGTH]=parasitic_data[i-1][LENGTH];
61 }
62 }
63
64 if ((randomisation_method & DIRECTOR_POSITION) == DIRECTOR_POSITION) /* 16 */
65 {
66 old_boom_length=parasitic_data[parasites][X];
67 y=1+0.02*max_percent*(randreal()-0.5);
68 new_boom_length=old_boom_length*y;
69 if(new_boom_length > max_boom_length)
70 new_boom_length=max_boom_length;
71 /* rearrange directors */
72 for(i=2; i<=parasites; ++i)
73 {
74 y=1+0.02*max_percent*(randreal()-0.5);
75 parasitic_data[i][X]*=y*(new_boom_length/old_boom_length);
76 }
77 }
78 if ((randomisation_method & ALL_ELEMENT_LENGTHS_IDENTICAL)==ALL_ELEMENT_LENGTHS_IDENTICAL) /* 32 */
79 {
80 y=1+0.02*max_percent*(randreal()-0.5);
81 for(i=1; i<=driven; ++i)
82 driven_data[i][LENGTH]*=y;
83 for(i=1; i<=parasites; ++i)
84 parasitic_data[i][LENGTH]=driven_data[1][LENGTH];
85 }
86 if ((randomisation_method & LINEAR_TAPER)==LINEAR_TAPER) /* 64 */
87 {
88 a=1+(0.1*randreal()); /* 1.00 to 1.1 */
89 taper=(a-1)/driven_data[1][X];
90 parasitic_data[1][LENGTH]=a*driven_data[1][3]; /* reflector = a*driven */
91 for(i=2; i<=parasites; ++i)
92 parasitic_data[i][LENGTH]=parasitic_data[1][3]-taper*(parasitic_data[i][X]-driven_data[1][X]);
93 }
94
95 if ((randomisation_method & RESONATE_DRIVEN)==RESONATE_DRIVEN) /* 128 */
96 {
97 if(run_first_time==1)
98 {
99 elements=driven+parasites;
100 z=dmatrix(1L,(long)elements,2L,2L*(long)elements);
101 l=0.44*lambda;
102 do
103 {
104 driven_data[1][LENGTH]=l;
105 self_impedance(1, frequency*1e6,driven,parasites,driven_data,z);
106 l+=0.00005*lambda;
107 driven_data[1][LENGTH]=l;
108 x=z[1][2];
109 }while(z[1][2]<0.0);
110 printf("Driven element set to :l=%f m = %f wavlengths\n",l,l/lambda);
111 free_dmatrix(z,1L,elements,1L,2L*elements);
112 }
113 }
114 #ifdef DEBUG
115 if(errno)
116 {
117 fprintf(stderr,"Errno =%d in randomis.c\n", errno);
118 exit(1);
119 }
120 #endif
121 }
122
123