forked from johannesgerer/jburkardt-cpp
-
Notifications
You must be signed in to change notification settings - Fork 0
/
analemma.html
244 lines (207 loc) · 5.68 KB
/
analemma.html
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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
<html>
<head>
<title>
ANALEMMA - Evaluating the Equation of Time
</title>
</head>
<body bgcolor="#EEEEEE" link="#CC0000" alink="#FF3300" vlink="#000055">
<h1 align = "center">
ANALEMMA <br> Evaluating the Equation of Time
</h1>
<hr>
<p>
<b>ANALEMMA</b>
is a C++ program which evaluates the equation of time,
by Brian Tung.
</p>
<p>
The program can compute and plot an analemma curve for
various orbital parameters. The analemma is the curve traced by the position
of the sun, measured at clock noon, over a year.
</p>
<p>
The program creates data and command files
which must be processed by the GNUPLOT program:
<pre>
gnuplot < analemma_commands.txt
</pre>
which will create PNG images of the analemma, the declination, and the
equation of time.
</p>
<h3 align = "center">
Usage:
</h3>
<p>
<blockquote>
<b>analemma</b> <i>options</i>
</blockquote>
where the allowable options include
<ul>
<li>
<b>-e</b> <i>ecc</i>, the eccentricity;
</li>
<li>
<b>-l</b> <i>lon</i>, the perihelion longitude in degrees;
</li>
<li>
<b>-o</b> <i>obliq</i>, the axial obliquity in degrees;
</li>
<li>
<b>-h</b> <i>ecc</i>, print the usage information;
</li>
</ul>
</p>
<p>
The program with no options uses the following default values:
<ul>
<li>
eccentricity = 0.01671;
</li>
<li>
longitude of perihelion = 1.347 radians = 77.18 degrees;
</li>
<li>
axial obliquity = 0.4091 radians = 23.44 degrees;
</li>
</ul>
</p>
<h3 align = "center">
Licensing:
</h3>
<p>
The computer code and data files described and made available on this web page
are distributed under
<a href = "../../txt/gnu_lgpl.txt">the GNU LGPL license.</a>
</p>
<h3 align = "center">
Languages:
</h3>
<p>
<b>ANALEMMA</b> is available in
<a href = "../../c_src/analemma/analemma.html">a C version</a> and
<a href = "../../cpp_src/analemma/analemma.html">a C++ version</a> and
<a href = "../../f77_src/analemma/analemma.html">a FORTRAN77 version</a> and
<a href = "../../f_src/analemma/analemma.html">a FORTRAN90 version</a> and
<a href = "../../m_src/analemma/analemma.html">a MATLAB version</a>.
</p>
<h3 align = "center">
Related Data and Programs:
</h3>
<p>
<a href = "../../cpp_src/calendar_rd/calendar_rd.html">
CALENDAR_RD</a>,
a C++ program which
computes the representation of a given date in a
number of calendrical systems,
by Edward Reingold, Nachum Dershowitz.
</p>
<p>
<a href = "../../cpp_src/calpak/calpak.html">
CALPAK</a>,
a C++ library which
makes various calendar calculations;
</p>
<p>
<a href = "../../datasets/dates/dates.html">
DATES</a>,
a dataset directory which
contains lists of dates in various calendar systems.
</p>
<p>
<a href = "../../cpp_src/gnuplot/gnuplot.html">
GNUPLOT</a>,
C++ programs which
illustrate the use of the gnuplot graphics program.
</p>
<p>
<a href = "../../cpp_src/weekday/weekday.html">
WEEKDAY</a>,
a C++ library which
determines the day of the week corresponding to a given date,
such as 14 October 1066, Julian calendar, ... which was a Saturday.
</p>
<h3 align = "center">
Author:
</h3>
<p>
Original C version by Brian Tung.
C++ version by John Burkardt.
</p>
<h3 align = "center">
Reference:
</h3>
<p>
<ol>
<li>
Brian Tung,<br>
Figure Eight in the Sky, a new perspective on an old fascination,<br>
Astronomical Games, August 2002,<br>
http://www.astronomycorner.net/games/analemma.html.
</li>
</ol>
</p>
<h3 align = "center">
Source Code:
</h3>
<p>
<ul>
<li>
<a href = "analemma.cpp">analemma.cpp</a>, the source code.
</li>
<li>
<a href = "analemma.sh">analemma.sh</a>,
BASH commands to compile the source code.
</li>
</ul>
</p>
<h3 align = "center">
Examples and Tests:
</h3>
<p>
<ul>
<li>
<a href = "analemma_data.txt">analemma_data.txt</a>
the data file.
</li>
<li>
<a href = "analemma_commands.txt">analemma_commands.txt</a>,
the command file.
</li>
<li>
<a href = "analemma.png">analemma.png</a>,
the PNG file of the analemma, created by GNUPLOT.
</li>
<li>
<a href = "declination.png">declination.png</a>,
the PNG file of the declination, created by GNUPLOT.
</li>
<li>
<a href = "eot.png">eot.png</a>,
the PNG file of the equation of time, created by GNUPLOT.
</li>
</ul>
<h3 align = "center">
List of Routines:
</h3>
<p>
<ul>
<li>
<b>MAIN</b> is the main program for ANALEMMA.
</li>
<li>
<b>TIMESTAMP</b> prints the current YMDHMS date as a time stamp.
</li>
</ul>
</p>
<p>
You can go up one level to <a href = "../cpp_src.html">
the C++ source codes</a>.
</p>
<hr>
<i>
Last revised on 06 January 2013.
</i>
<!-- John Burkardt -->
</body>
<!-- Initial HTML skeleton created by HTMLINDEX. -->
</html>