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author | KatolaZ <katolaz@freaknet.org> | 2017-09-27 15:06:31 +0100 |
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committer | KatolaZ <katolaz@freaknet.org> | 2017-09-27 15:06:31 +0100 |
commit | 3aee2fd43e3059a699af2b63c6f2395e5a55e515 (patch) | |
tree | 58c95505a0906ed9cfa694f9dbd319403fd8f01d /doc/johnson_cycles.1.html |
First commit on github -- NetBunch 1.0
Diffstat (limited to 'doc/johnson_cycles.1.html')
-rw-r--r-- | doc/johnson_cycles.1.html | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/doc/johnson_cycles.1.html b/doc/johnson_cycles.1.html new file mode 100644 index 0000000..225f95c --- /dev/null +++ b/doc/johnson_cycles.1.html @@ -0,0 +1,268 @@ +<!DOCTYPE html> +<html> +<head> + <meta http-equiv='content-type' value='text/html;charset=utf8'> + <meta name='generator' value='Ronn/v0.7.3 (http://github.com/rtomayko/ronn/tree/0.7.3)'> + <title>johnson_cycles(1) - Enumerate the simple cycles of a graph</title> + <style type='text/css' media='all'> + /* style: man */ + body#manpage {margin:0} + .mp {max-width:100ex;padding:0 9ex 1ex 4ex} + .mp p,.mp pre,.mp ul,.mp ol,.mp dl {margin:0 0 20px 0} + .mp h2 {margin:10px 0 0 0} + .mp > p,.mp > pre,.mp > ul,.mp > ol,.mp > dl {margin-left:8ex} + .mp h3 {margin:0 0 0 4ex} + .mp dt {margin:0;clear:left} + .mp dt.flush {float:left;width:8ex} + .mp dd {margin:0 0 0 9ex} + .mp h1,.mp h2,.mp h3,.mp h4 {clear:left} + .mp pre {margin-bottom:20px} + .mp pre+h2,.mp pre+h3 {margin-top:22px} + .mp h2+pre,.mp h3+pre {margin-top:5px} + .mp img {display:block;margin:auto} + .mp h1.man-title {display:none} + .mp,.mp code,.mp pre,.mp tt,.mp kbd,.mp samp,.mp h3,.mp h4 {font-family:monospace;font-size:14px;line-height:1.42857142857143} + .mp h2 {font-size:16px;line-height:1.25} + .mp h1 {font-size:20px;line-height:2} + .mp {text-align:justify;background:#fff} + .mp,.mp code,.mp pre,.mp pre code,.mp tt,.mp kbd,.mp samp {color:#131211} + .mp h1,.mp h2,.mp h3,.mp h4 {color:#030201} + .mp u {text-decoration:underline} + .mp code,.mp strong,.mp b {font-weight:bold;color:#131211} + .mp em,.mp var {font-style:italic;color:#232221;text-decoration:none} + .mp a,.mp a:link,.mp a:hover,.mp a code,.mp a pre,.mp a tt,.mp a kbd,.mp a samp {color:#0000ff} + .mp b.man-ref {font-weight:normal;color:#434241} + .mp pre {padding:0 4ex} + .mp pre code {font-weight:normal;color:#434241} + .mp h2+pre,h3+pre {padding-left:0} + ol.man-decor,ol.man-decor li {margin:3px 0 10px 0;padding:0;float:left;width:33%;list-style-type:none;text-transform:uppercase;color:#999;letter-spacing:1px} + ol.man-decor {width:100%} + ol.man-decor li.tl {text-align:left} + ol.man-decor li.tc {text-align:center;letter-spacing:4px} + ol.man-decor li.tr {text-align:right;float:right} + </style> + <style type='text/css' media='all'> + /* style: toc */ + .man-navigation {display:block !important;position:fixed;top:0;left:113ex;height:100%;width:100%;padding:48px 0 0 0;border-left:1px solid #dbdbdb;background:#eee} + .man-navigation a,.man-navigation a:hover,.man-navigation a:link,.man-navigation a:visited {display:block;margin:0;padding:5px 2px 5px 30px;color:#999;text-decoration:none} + .man-navigation a:hover {color:#111;text-decoration:underline} + </style> +</head> +<!-- + The following styles are deprecated and will be removed at some point: + div#man, div#man ol.man, div#man ol.head, div#man ol.man. + + The .man-page, .man-decor, .man-head, .man-foot, .man-title, and + .man-navigation should be used instead. +--> +<body id='manpage'> + <div class='mp' id='man'> + + <div class='man-navigation' style='display:none'> + <a href="#NAME">NAME</a> + <a href="#SYNOPSIS">SYNOPSIS</a> + <a href="#DESCRIPTION">DESCRIPTION</a> + <a href="#PARAMETERS">PARAMETERS</a> + <a href="#OUTPUT">OUTPUT</a> + <a href="#EXAMPLES">EXAMPLES</a> + <a href="#SEE-ALSO">SEE ALSO</a> + <a href="#REFERENCES">REFERENCES</a> + <a href="#AUTHORS">AUTHORS</a> + </div> + + <ol class='man-decor man-head man head'> + <li class='tl'>johnson_cycles(1)</li> + <li class='tc'>www.complex-networks.net</li> + <li class='tr'>johnson_cycles(1)</li> + </ol> + + <h2 id="NAME">NAME</h2> +<p class="man-name"> + <code>johnson_cycles</code> - <span class="man-whatis">Enumerate the simple cycles of a graph</span> +</p> + +<h2 id="SYNOPSIS">SYNOPSIS</h2> + +<p><code>johnson_cycles</code> <var>graph_in</var> [<var>max_length</var> [SHOW]]</p> + +<h2 id="DESCRIPTION">DESCRIPTION</h2> + +<p><code>johnson_cycles</code> enumerates all the simple cycles of the graph given +on input, and prints the total number of cycles of each length. If +<var>max_length</var> is provided, <code>johnson_cycles</code> ignores any cycle whose +length is larger than <var>max_length</var>. If <code>SHOW</code> is given as third +argument, all the found cycles are printed on STDERR as soon as they +are found.</p> + +<h2 id="PARAMETERS">PARAMETERS</h2> + +<ul> +<li><p><var>graph_in</var>: + input graph (edge list) if equal to <code>-</code> (dash), read the edge list + from STDIN.</p></li> +<li><p><var>max_length</var>: The maximum length of cycles to count/print. If not + provided, <code>johnson_cycles</code> tries to find all the cycles of the + graph (see the <strong>WARNING</strong> in the section <a href="#OUTPUT" title="OUTPUT" data-bare-link="true">OUTPUT</a> below).</p></li> +<li><p>SHOW: + If the third (optional) parameter is equal to <code>SHOW</code>, the program + will dump on the standard error all the cycles found.</p></li> +</ul> + + +<h2 id="OUTPUT">OUTPUT</h2> + +<p><code>johnson_cycles</code> prints on the standard output the number of cycles of +each length, in the format:</p> + +<pre><code> 2 N_2 + 3 N_3 + 4 N_4 + 5 N_5 + ... +</code></pre> + +<p>where 2, 3, 4, 5... is the cycle lengths and N_2, N_3, N_4, N_5... is +(twice) the number of cycles of that length. If <code>SHOW</code> is given, each +cycle is also printed on STDERR as soon as it is found, in the format:</p> + +<pre><code>node_l node_(l-1) node_(l-2) ... node_0 +</code></pre> + +<p>where <code>node_l</code>, <code>node_(l-1)</code>, etc. are the labels of the nodes +belonging to the cycle which starts at node <code>node_0</code>.</p> + +<p><strong>WARNING</strong>: If the second parameter <var>max_length</var> is not provided, + <code>johnson_cycles</code> will try to enumerate <strong>all</strong> the cycles of the + graph. In general, this might take a time <strong>exponential</strong> in the + number of nodes and edges of the graph. As a consequence, specifying + a maximum length is <strong>highly recommended</strong> if you are not interested + in finding the number of cycles of any length.</p> + +<h2 id="EXAMPLES">EXAMPLES</h2> + +<p>We can count the cycle of any length in the graph of Florentine +families using the command:</p> + +<pre><code> $ johnson_cycles florentine.net + 2 20 + 3 6 + 4 4 + 5 6 + 6 10 + 7 20 + 8 22 + 9 8 + 10 2 + 11 0 + 12 0 + 13 0 + 14 0 + 15 0 + 16 0 + $ +</code></pre> + +<p>The output means that the graph has 20 cycles of length 2 (edges), +6/2=3 cycles of length 3, 4/2=2 cycles of length 4, and so on. We +could otherwise focus on the cycles of length up to 5 and have each +cycle printed on output:</p> + +<pre><code> $ johnson_cycles florentine.net 5 SHOW + 8 0 + 5 1 + 8 15 6 1 + 8 12 15 6 1 + 6 1 + 6 15 12 8 1 + 6 15 8 1 + 8 1 + 8 12 14 4 2 + .... + 15 12 + 2 20 + 3 6 + 4 4 + 5 6 + $ +</code></pre> + +<p>Apart from the degenerate cycles like "8 0", "5 1", etc., +corresponding to the cycles obtained by traversing the same undirected +edge in the two possible directions, we see in that list some of the +cycles of length 4 (such as "8 15 6 1") and of length 5 (such as "8 12 +15 6 1").</p> + +<p>The enumeration of all the cycles is normally impractical on larger +graphs, so it is highly recommended to limit the search to short +sizes. For instance, the command:</p> + +<pre><code> $ johnson_cycles er_1000_5000.net 6 + 2 5000 + 3 340 + 4 2406 + 5 19416 + 6 160554 + $ +</code></pre> + +<p>will require less than one second on a modern desktop computer, but +the command:</p> + +<pre><code> $ johnson_cycles er_1000_5000.net 7 + 2 5000 + 3 340 + 4 2406 + 5 19416 + 6 160554 + 7 1360104 + $ +</code></pre> + +<p>will probably take about 15 seconds, while:</p> + +<pre><code> $ johnson_cycles er_1000_5000.net 8 + 2 5000 + 3 340 + 4 2406 + 5 19416 + 6 160554 + 7 1360104 + 8 11743500 + $ +</code></pre> + +<p>will run for more than 2 minutes, and larger cycle lengths will +require exponentially more time.</p> + +<h2 id="SEE-ALSO">SEE ALSO</h2> + +<p><a class="man-ref" href="f3m.1.html">f3m<span class="s">(1)</span></a>, <a class="man-ref" href="shortest.1.html">shortest<span class="s">(1)</span></a></p> + +<h2 id="REFERENCES">REFERENCES</h2> + +<ul> +<li><p>D. B. Johnson. "Finding All the Elementary Circuits of a Directed +Graph". SIAM J. Comput. 4 (1975), 77-84.</p></li> +<li><p>V. Latora, V. Nicosia, G. Russo, "Complex Networks: Principles, +Methods and Applications", Chapter 8, Cambridge University Press +(2017)</p></li> +<li><p>V. Latora, V. Nicosia, G. Russo, "Complex Networks: Principles, +Methods and Applications", Appendix 15, Cambridge University Press +(2017)</p></li> +</ul> + + +<h2 id="AUTHORS">AUTHORS</h2> + +<p>(c) Vincenzo 'KatolaZ' Nicosia 2009-2017 <code><v.nicosia@qmul.ac.uk></code>.</p> + + + <ol class='man-decor man-foot man foot'> + <li class='tl'>www.complex-networks.net</li> + <li class='tc'>September 2017</li> + <li class='tr'>johnson_cycles(1)</li> + </ol> + + </div> +</body> +</html> |