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<html><head><title>dlib C++ Library - bayes_net_from_disk_ex.cpp</title></head><body bgcolor='white'><pre> |
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<font color='#009900'>// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt |
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</font><font color='#009900'>/* |
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This is an example illustrating the use of the Bayesian Network |
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inference utilities found in the dlib C++ library. In this example |
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we load a saved Bayesian Network from disk. |
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*/</font> |
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<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>dlib<font color='#5555FF'>/</font>bayes_utils.h<font color='#5555FF'>></font> |
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<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>dlib<font color='#5555FF'>/</font>graph_utils.h<font color='#5555FF'>></font> |
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<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>dlib<font color='#5555FF'>/</font>graph.h<font color='#5555FF'>></font> |
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<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>dlib<font color='#5555FF'>/</font>directed_graph.h<font color='#5555FF'>></font> |
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<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>iostream<font color='#5555FF'>></font> |
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<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>fstream<font color='#5555FF'>></font> |
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<font color='#0000FF'>using</font> <font color='#0000FF'>namespace</font> dlib; |
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<font color='#0000FF'>using</font> <font color='#0000FF'>namespace</font> std; |
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<font color='#009900'>// ---------------------------------------------------------------------------------------- |
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</font> |
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<font color='#0000FF'><u>int</u></font> <b><a name='main'></a>main</b><font face='Lucida Console'>(</font><font color='#0000FF'><u>int</u></font> argc, <font color='#0000FF'><u>char</u></font><font color='#5555FF'>*</font><font color='#5555FF'>*</font> argv<font face='Lucida Console'>)</font> |
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<b>{</b> |
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<font color='#0000FF'>try</font> |
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<b>{</b> |
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<font color='#009900'>// This statement declares a bayesian network called bn. Note that a bayesian network |
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</font> <font color='#009900'>// in the dlib world is just a directed_graph object that contains a special kind |
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</font> <font color='#009900'>// of node called a bayes_node. |
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</font> directed_graph<font color='#5555FF'><</font>bayes_node<font color='#5555FF'>></font>::kernel_1a_c bn; |
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<font color='#0000FF'>if</font> <font face='Lucida Console'>(</font>argc <font color='#5555FF'>!</font><font color='#5555FF'>=</font> <font color='#979000'>2</font><font face='Lucida Console'>)</font> |
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<b>{</b> |
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cout <font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>You must supply a file name on the command line. The file should </font>" |
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<font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>contain a serialized Bayesian Network</font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> endl; |
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<font color='#0000FF'>return</font> <font color='#979000'>1</font>; |
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<b>}</b> |
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ifstream <font color='#BB00BB'>fin</font><font face='Lucida Console'>(</font>argv[<font color='#979000'>1</font>],ios::binary<font face='Lucida Console'>)</font>; |
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<font color='#009900'>// Note that the saved networks produced by the <a href="bayes_net_gui_ex.cpp.html">bayes_net_gui_ex.cpp</a> example can be deserialized |
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</font> <font color='#009900'>// into a network. So you can make your networks using that GUI if you like. |
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</font> cout <font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>Loading the network from disk...</font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> endl; |
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<font color='#BB00BB'>deserialize</font><font face='Lucida Console'>(</font>bn, fin<font face='Lucida Console'>)</font>; |
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cout <font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>Number of nodes in the network: </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> bn.<font color='#BB00BB'>number_of_nodes</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> endl; |
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<font color='#009900'>// Let's compute some probability values using the loaded network using the join tree (aka. Junction |
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</font> <font color='#009900'>// Tree) algorithm. |
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</font> |
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<font color='#009900'>// First we need to create an undirected graph which contains set objects at each node and |
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</font> <font color='#009900'>// edge. This long declaration does the trick. |
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</font> <font color='#0000FF'>typedef</font> graph<font color='#5555FF'><</font>dlib::set<font color='#5555FF'><</font><font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font><font color='#5555FF'>></font>::compare_1b_c, dlib::set<font color='#5555FF'><</font><font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font><font color='#5555FF'>></font>::compare_1b_c<font color='#5555FF'>></font>::kernel_1a_c join_tree_type; |
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join_tree_type join_tree; |
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<font color='#009900'>// Now we need to populate the join_tree with data from our bayesian network. The next two |
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</font> <font color='#009900'>// function calls do this. Explaining exactly what they do is outside the scope of this |
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</font> <font color='#009900'>// example. Just think of them as filling join_tree with information that is useful |
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</font> <font color='#009900'>// later on for dealing with our bayesian network. |
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</font> <font color='#BB00BB'>create_moral_graph</font><font face='Lucida Console'>(</font>bn, join_tree<font face='Lucida Console'>)</font>; |
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<font color='#BB00BB'>create_join_tree</font><font face='Lucida Console'>(</font>join_tree, join_tree<font face='Lucida Console'>)</font>; |
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<font color='#009900'>// Now we have a proper join_tree we can use it to obtain a solution to our |
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</font> <font color='#009900'>// bayesian network. Doing this is as simple as declaring an instance of |
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</font> <font color='#009900'>// the bayesian_network_join_tree object as follows: |
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</font> bayesian_network_join_tree <font color='#BB00BB'>solution</font><font face='Lucida Console'>(</font>bn, join_tree<font face='Lucida Console'>)</font>; |
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<font color='#009900'>// now print out the probabilities for each node |
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</font> cout <font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>Using the join tree algorithm:\n</font>"; |
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<font color='#0000FF'>for</font> <font face='Lucida Console'>(</font><font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> i <font color='#5555FF'>=</font> <font color='#979000'>0</font>; i <font color='#5555FF'><</font> bn.<font color='#BB00BB'>number_of_nodes</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <font color='#5555FF'>+</font><font color='#5555FF'>+</font>i<font face='Lucida Console'>)</font> |
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<b>{</b> |
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<font color='#009900'>// print out the probability distribution for node i. |
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</font> cout <font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>p(node </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> i <font color='#5555FF'><</font><font color='#5555FF'><</font>"<font color='#CC0000'>) = </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> solution.<font color='#BB00BB'>probability</font><font face='Lucida Console'>(</font>i<font face='Lucida Console'>)</font>; |
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<b>}</b> |
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<b>}</b> |
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<font color='#0000FF'>catch</font> <font face='Lucida Console'>(</font>exception<font color='#5555FF'>&</font> e<font face='Lucida Console'>)</font> |
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<b>{</b> |
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cout <font color='#5555FF'><</font><font color='#5555FF'><</font> "<font color='#CC0000'>exception thrown: </font>" <font color='#5555FF'><</font><font color='#5555FF'><</font> e.<font color='#BB00BB'>what</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font color='#5555FF'><</font><font color='#5555FF'><</font> endl; |
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<font color='#0000FF'>return</font> <font color='#979000'>1</font>; |
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<b>}</b> |
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<b>}</b> |
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</pre></body></html> |
