1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
/* $Id: x17c.c,v 1.16 2002/12/03 08:39:24 airwin Exp $
* Plots a simple stripchart with four pens.
*/
#include "plcdemos.h"
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#else
# ifdef HAS_POLL
# include <poll.h>
# endif
#endif
/* Variables for holding error return info from PLplot */
static PLINT errcode;
static char errmsg[160];
/*--------------------------------------------------------------------------*\
* main program
\*--------------------------------------------------------------------------*/
int
main(int argc, char *argv[])
{
PLINT id1, id2, n, autoy, acc, nsteps = 1000;
PLFLT y1, y2, y3, y4, ymin, ymax, xlab, ylab;
PLFLT t, tmin, tmax, tjump, dt, noise;
PLINT colbox, collab, colline[4], styline[4];
char *legline[4], toplab[20];
double drand48(void);
/* plplot initialization */
/* Parse and process command line arguments */
(void) plParseOpts(&argc, argv, PL_PARSE_FULL);
/* If db is used the plot is much more smooth. However, because of the
async X behaviour, one does not have a real-time scripcharter.
*/
plsetopt("db", "");
plsetopt("np", "");
/* User sets up plot completely except for window and data
* Eventually settings in place when strip chart is created will be
* remembered so that multiple strip charts can be used simultaneously.
*/
/* Specify some reasonable defaults for ymin and ymax */
/* The plot will grow automatically if needed (but not shrink) */
ymin = -0.1;
ymax = 0.1;
/* Specify initial tmin and tmax -- this determines length of window. */
/* Also specify maximum jump in t */
/* This can accomodate adaptive timesteps */
tmin = 0.;
tmax = 10.;
tjump = 0.3; /* percentage of plot to jump */
/* Axes options same as plbox. */
/* Only automatic tick generation and label placement allowed */
/* Eventually I'll make this fancier */
colbox = 1;
collab = 3;
styline[0] = colline[0] = 2; /* pens color and line style */
styline[1] = colline[1] = 3;
styline[2] = colline[2] = 4;
styline[3] = colline[3] = 5;
legline[0] = "sum"; /* pens legend */
legline[1] = "sin";
legline[2] = "sin*noi";
legline[3] = "sin+noi";
xlab = 0.; ylab = 0.25; /* legend position */
autoy = 1; /* autoscale y */
acc = 1; /* don't scrip, accumulate */
/* Initialize plplot */
plinit();
pladv(0);
plvsta();
/* Register our error variables with PLplot */
/* From here on, we're handling all errors here */
plsError(&errcode, errmsg);
plstripc(&id1, "bcnst", "bcnstv",
tmin, tmax, tjump, ymin, ymax,
xlab, ylab,
autoy, acc,
colbox, collab,
colline, styline, legline,
"t", "", "Strip chart demo");
if (errcode) {
fprintf(stderr, "%s\n", errmsg);
exit(1);
}
/* Let plplot handle errors from here on */
plsError(NULL, NULL);
autoy = 0; /* autoscale y */
acc = 1; /* accumulate */
/* This is to represent a loop over time */
/* Let's try a random walk process */
y1 = y2 = y3 = y4 = 0.0;
dt = 0.1;
for (n = 0; n < nsteps; n++) {
#ifdef HAVE_USLEEP
usleep(10000); /* wait a little (10 ms) to simulate time elapsing */
#else
# ifdef HAS_POLL
poll(0,0,10);
# endif
#endif
t = (double)n * dt;
noise = drand48() - 0.5;
y1 = y1 + noise;
y2 = sin(t*PI/18.);
y3 = y2 * noise;
y4 = y2 + noise/3.;
/* There is no need for all pens to have the same number of
points or beeing equally time spaced. */
if (n%2)
plstripa(id1, 0, t, y1);
if (n%3)
plstripa(id1, 1, t, y2);
if (n%4)
plstripa(id1, 2, t, y3);
if (n%5)
plstripa(id1, 3, t, y4);
pleop(); /* use double buffer (-db on command line) */
}
/* Destroy strip chart and it's memory */
plstripd(id1);
plend();
exit(0);
}
|
