Codebase list cppad / upstream/2015.00.00.7 doc / harmonic.cpp.xml
upstream/2015.00.00.7

Tree @upstream/2015.00.00.7 (Download .tar.gz)

harmonic.cpp.xml @upstream/2015.00.00.7 — raw · history · blame 

  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
245
246
<?xml version='1.0'?>
<html xmlns='http://www.w3.org/1999/xhtml'
      xmlns:math='http://www.w3.org/1998/Math/MathML'
>
<head>
<title>Multi-Threaded Implementation of Summation of 1/i</title>
<meta http-equiv='Content-Type' content='text/html' charset='utf-8'/>
<meta name="description" id="description" content="Multi-Threaded Implementation of Summation of 1/i"/>
<meta name="keywords" id="keywords" content=" harmonic multi_thread thread multi multi-threaded implementation of summation 1/i syntax ok sum num_sum num_threads source "/>
<style type='text/css'>
body { color : black }
body { background-color : white }
A:link { color : blue }
A:visited { color : purple }
A:active { color : purple }
</style>
<script type='text/javascript' language='JavaScript' src='_harmonic.cpp_xml.js'>
</script>
</head>
<body>
<table><tr>
<td>
<a href="http://www.coin-or.org/CppAD/" target="_top"><img border="0" src="_image.gif"/></a>
</td>
<td><a href="team_example.cpp.xml" target="_top">Prev</a>
</td><td><a href="harmonic_time.cpp.xml" target="_top">Next</a>
</td><td>
<select onchange='choose_across0(this)'>
<option>Index-&gt;</option>
<option>contents</option>
<option>reference</option>
<option>index</option>
<option>search</option>
<option>external</option>
</select>
</td>
<td>
<select onchange='choose_up0(this)'>
<option>Up-&gt;</option>
<option>CppAD</option>
<option>multi_thread</option>
<option>thread_test.cpp</option>
<option>harmonic.cpp</option>
</select>
</td>
<td>
<select onchange='choose_down3(this)'>
<option>CppAD-&gt;</option>
<option>Install</option>
<option>Introduction</option>
<option>AD</option>
<option>ADFun</option>
<option>preprocessor</option>
<option>multi_thread</option>
<option>library</option>
<option>ipopt_solve</option>
<option>Example</option>
<option>speed</option>
<option>Appendix</option>
</select>
</td>
<td>
<select onchange='choose_down2(this)'>
<option>multi_thread-&gt;</option>
<option>parallel_ad</option>
<option>thread_test.cpp</option>
</select>
</td>
<td>
<select onchange='choose_down1(this)'>
<option>thread_test.cpp-&gt;</option>
<option>a11c_openmp.cpp</option>
<option>a11c_bthread.cpp</option>
<option>a11c_pthread.cpp</option>
<option>simple_ad_openmp.cpp</option>
<option>simple_ad_bthread.cpp</option>
<option>simple_ad_pthread.cpp</option>
<option>team_example.cpp</option>
<option>harmonic.cpp</option>
<option>multi_newton.cpp</option>
<option>team_thread.hpp</option>
</select>
</td>
<td>
<select onchange='choose_down0(this)'>
<option>harmonic.cpp-&gt;</option>
<option>harmonic_time.cpp</option>
<option>harmonic_work.cpp</option>
</select>
</td>
<td>
<select onchange='choose_current0(this)'>
<option>Headings-&gt;</option>
<option>Syntax</option>
<option>Summation</option>
<option>ok</option>
<option>sum</option>
<option>num_sum</option>
<option>num_threads</option>
<option>Contents</option>
<option>Source</option>
</select>
</td>
</tr></table><br/>








<center><b><big><big>Multi-Threaded Implementation of Summation of 1/i</big></big></b></center>
<br/>
<b><big><a name="Syntax" id="Syntax">Syntax</a></big></b>

<br/>

<code><i><font color="black"><span style='white-space: nowrap'>ok</span></font></i><font color="blue"><span style='white-space: nowrap'>&#xA0;=&#xA0;harmonic(</span></font><i><font color="black"><span style='white-space: nowrap'>sum</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>num_sum</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>num_threads</span></font></i><font color="blue"><span style='white-space: nowrap'>)</span></font></code>


<br/>
<br/>
<b><big><a name="Summation" id="Summation">Summation</a></big></b>
<br/>
Multi-threaded computation of the summation that defines the harmonic series 

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><mrow>
<mi mathvariant='italic'>s</mi>
<mo stretchy="false">=</mo>
<mn>1</mn>
<mo stretchy="false">+</mo>
<mn>1</mn>
<mo stretchy="false">/</mo>
<mn>2</mn>
<mo stretchy="false">+</mo>
<mn>1</mn>
<mo stretchy="false">/</mo>
<mn>3</mn>
<mo stretchy="false">+</mo>
<mo stretchy="false">.</mo>
<mo stretchy="false">.</mo>
<mo stretchy="false">.</mo>
<mo stretchy="false">+</mo>
<mn>1</mn>
<mo stretchy="false">/</mo>
<mi mathvariant='italic'>n</mi>
</mrow></math>

<br/>
<b><big><a name="ok" id="ok">ok</a></big></b>
<br/>
This return value has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;bool&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>ok</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
If this return value is false, an error occurred during <code><font color="blue">harmonic</font></code>.

<br/>
<br/>
<b><big><a name="sum" id="sum">sum</a></big></b>
<br/>
This argument has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;double&amp;&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>sum</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
The input value of the argument does not matter.
Upon return it is the value of the summation; i.e. 
<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow>
<mi mathvariant='italic'>s</mi>
</mrow></math>

.

<br/>
<br/>
<b><big><a name="num_sum" id="num_sum">num_sum</a></big></b>
<br/>
This argument has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;size_t&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>num_sum</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
It specifies the number of terms in the summation; i.e. 
<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow>
<mi mathvariant='italic'>n</mi>
</mrow></math>

.

<br/>
<br/>
<b><big><a name="num_threads" id="num_threads">num_threads</a></big></b>
<br/>
This argument has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;size_t&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>num_threads</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
It specifies the number of threads that are available for this test.
If it is zero, the test is run without a multi-threading environment.

<br/>
<br/>
<b><big><a name="Contents" id="Contents">Contents</a></big></b>
<br/>
<table>
<tr><td><a href="harmonic_time.cpp.xml" target="_top">harmonic_time.cpp</a></td><td>Timing&#xA0;Test&#xA0;of&#xA0;Multi-Threaded&#xA0;Summation&#xA0;of&#xA0;1/i</td></tr><tr><td><a href="harmonic_work.cpp.xml" target="_top">harmonic_work.cpp</a></td><td>Multi-threading&#xA0;Sum&#xA0;of&#xA0;1/i&#xA0;Utility&#xA0;Routines</td></tr></table><br/>
<b><big><a name="Source" id="Source">Source</a></big></b>

<code><font color="blue">
<br/>
<pre style='display:inline'> 
// general purpose multi-threading interface
# include &quot;team_thread.hpp&quot;
// special utilities for the harmonic problem
# include &quot;harmonic_work.hpp&quot;

bool harmonic(double&amp; sum, size_t num_sum, size_t num_threads)
{	// sum = 1/num_sum + 1/(num_sum-1) + ... + 1
	bool ok = true;

	// setup the work for num_threads_ threads
	ok &amp;= harmonic_setup(num_sum, num_threads);

	// now do the work for each thread
	if( num_threads &gt; 0 )
		team_work( harmonic_worker );
	else	harmonic_worker();

	// now combine the result for all the threads
	ok &amp;= harmonic_combine(sum);

	return ok;
}
</pre>

</font></code>


<hr/>Input File: multi_thread/harmonic.cpp

</body>
</html>