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<doc>
   <title>Algorithms</title>

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   <body>
      <br/><br/>

         <p>
            This page documents library components that are all basically just implementations of 
            mathematical functions or algorithms that don't fit in any of the other pages
            of the dlib documentation.  So this includes things like checksums, cryptographic hashes, 
            optimization, sorting, etc.
         </p>

   </body>

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   <menu width="150">
    <top>
      <section>
         <name>Tools</name>
         <item>bigint</item> 
         <item>crc32</item> 
         <item>rand</item> 
         <item>running_stats</item> 
         <item>running_covariance</item> 
         <item>random_subset_selector</item> 
         <item nolink="true">
            <name>Optimization</name>
            <sub>
               <item>derivative</item> 
               <item>negate_function</item> 
               <item>make_line_search_function</item> 
               <item>poly_min_extrap</item> 
               <item>lagrange_poly_min_extrap</item> 
               <item>line_search</item> 
               <item>find_min</item> 
               <item>find_min_single_variable</item> 
               <item>find_min_using_approximate_derivatives</item> 
               <item>find_min_bobyqa</item> 
               <item>solve_qp_using_smo</item> 
               <item>find_max</item> 
               <item>find_max_single_variable</item> 
               <item>find_max_using_approximate_derivatives</item> 
               <item>find_max_bobyqa</item> 

               <item>cg_search_strategy</item>
               <item>bfgs_search_strategy</item>
               <item>lbfgs_search_strategy</item>
               <item>objective_delta_stop_strategy</item>
               <item>gradient_norm_stop_strategy</item>
            </sub>
         </item>
         <item nolink="true">
            <name>Quantum Computing</name>
            <sub>
               <item>quantum_register</item> 
               <item>gate</item> 
            </sub>
         </item>
         <item nolink="true">
            <name>Geometry</name>
            <sub>
               <item>rectangle</item> 
               <item>vector</item> 
               <item>point</item> 
               <item>rotate_point</item> 
               <item>point_rotator</item> 
               <item>get_rect</item> 
               <item>centered_rect</item> 
               <item>shrink_rect</item> 
               <item>grow_rect</item> 
               <item>translate_rect</item> 
               <item>resize_rect</item> 
               <item>resize_rect_width</item> 
               <item>resize_rect_height</item> 
               <item>move_rect</item> 
               <item>nearest_point</item> 
            </sub>
         </item>
         <item nolink="true">
            <name>Graph Utilities</name>
            <sub>
               <item>graph_contains_directed_cycle</item> 
               <item>graph_contains_undirected_cycle</item> 
               <item>create_moral_graph</item> 
               <item>triangulate_graph_and_find_cliques</item> 
               <item>graph_contains_length_one_cycle</item> 
               <item>find_connected_nodes</item> 
               <item>graph_is_connected</item> 
               <item>is_clique</item> 
               <item>is_maximal_clique</item> 
               <item>copy_graph_structure</item> 
               <item>edge</item> 
               <item>is_join_tree</item> 
               <item>create_join_tree</item> 
            </sub>
         </item>
         <item>hsort_array</item> 
         <item>isort_array</item> 
         <item>put_in_range</item> 
         <item>md5</item> 
         <item>median</item> 
         <item>qsort_array</item> 
         <item>square_root</item> 
         <item nolink="true">
            <name>Set Utilities</name>
            <sub>
               <item>set_intersection_size</item> 
               <item>set_intersection</item> 
               <item>set_union</item> 
               <item>set_difference</item> 
            </sub>
         </item>
      </section>

    </top>  
   </menu>

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   <components>
   
   <!-- ************************************************************************* -->
      
      <component>
         <name>derivative</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_abstract.h</spec_file>
         <description>
            This is a function that takes another function as input and returns
            a function object that numerically computes the derivative of the input function.
         </description>
                                 
      </component>


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      <component>
         <name>negate_function</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_abstract.h</spec_file>
         <description>
            This is a function that takes another function as input and returns
            a function object that computes the negation of the input function.
         </description>
                                 
      </component>


   <!-- ************************************************************************* -->
      
      <component>
         <name>make_line_search_function</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_line_search_abstract.h</spec_file>
         <description>
            This is a function that takes another function f(x) as input and returns
            a function object l(z) = f(start + z*direction).   It is useful for
            turning multi-variable functions into single-variable functions for
            use with the <a href="#line_search">line_search</a> routine.
         </description>
                                 
      </component>


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      <component>
         <name>poly_min_extrap</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_line_search_abstract.h</spec_file>
         <description>
            This function finds the 3rd degree polynomial that interpolates a 
            set of points and returns you the minimum of that polynomial.
         </description>
                                 
      </component>

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      <component>
         <name>lagrange_poly_min_extrap</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_line_search_abstract.h</spec_file>
         <description>
            This function finds the second order polynomial that interpolates a 
            set of points and returns you the minimum of that polynomial.
         </description>
                                 
      </component>

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      <component>
         <name>line_search</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_line_search_abstract.h</spec_file>
         <description>
            Performs a gradient based line search on a given function and returns the input
            that makes the function significantly smaller.
         </description>
                                 
      </component>


   <!-- ************************************************************************* -->

      <component>
         <name>cg_search_strategy</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_search_strategies_abstract.h</spec_file>
         <description>
                This object represents a strategy for determining which direction
                a <a href="#line_search">line search</a> should be carried out along.  This particular object
                is an implementation of the Polak-Ribiere conjugate gradient method
                for determining this direction.

                  <p>
                This method uses an amount of memory that is linear in the number
                of variables to be optimized.  So it is capable of handling problems
                with a very large number of variables.  However, it is generally
                not as good as the L-BFGS algorithm (see the 
                <a href="#lbfgs_search_strategy">lbfgs_search_strategy</a> class).
                  </p>
         </description>
         <examples>
            <example>optimization_ex.cpp.html</example>
         </examples>
                                 
      </component>

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      <component>
         <name>bfgs_search_strategy</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_search_strategies_abstract.h</spec_file>
         <description>
                This object represents a strategy for determining which direction
                a <a href="#line_search">line search</a> should be carried out along.  This particular object
                is an implementation of the BFGS quasi-newton method for determining 
                this direction.

                  <p>
                This method uses an amount of memory that is quadratic in the number
                of variables to be optimized.  It is generally very effective but 
                if your problem has a very large number of variables then it isn't 
                appropriate.  Instead You should try the <a href="#lbfgs_search_strategy">lbfgs_search_strategy</a>.
                  </p>
         </description>
         <examples>
            <example>optimization_ex.cpp.html</example>
         </examples>
                                 
      </component>

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      <component>
         <name>lbfgs_search_strategy</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_search_strategies_abstract.h</spec_file>
         <description>
                This object represents a strategy for determining which direction
                a <a href="#line_search">line search</a> should be carried out along.  This particular object
                is an implementation of the L-BFGS quasi-newton method for determining 
                this direction.

                  <p>
                This method uses an amount of memory that is linear in the number
                of variables to be optimized.  This makes it an excellent method 
                to use when an optimization problem has a large number of variables.
                  </p>
         </description>
         <examples>
            <example>optimization_ex.cpp.html</example>
         </examples>
                                 
      </component>

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      <component>
         <name>objective_delta_stop_strategy</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_stop_strategies_abstract.h</spec_file>
         <description>
                This object represents a strategy for deciding if an optimization
                algorithm should terminate.   This particular object looks at the 
                change in the objective function from one iteration to the next and 
                bases its decision on how large this change is.  If the change
                is below a user given threshold then the search stops.
         </description>
         <examples>
            <example>optimization_ex.cpp.html</example>
         </examples>
                                 
      </component>

   <!-- ************************************************************************* -->
      
      <component>
         <name>gradient_norm_stop_strategy</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_stop_strategies_abstract.h</spec_file>
         <description>
                This object represents a strategy for deciding if an optimization
                algorithm should terminate.   This particular object looks at the 
                norm (i.e. the length) of the current gradient vector and
                stops if it is smaller than a user given threshold.  
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->
      
      <component>
         <name>find_min</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_abstract.h</spec_file>
         <description>
             Performs an unconstrained minimization of a nonlinear function using 
             some search strategy (e.g. <a href="#bfgs_search_strategy">bfgs_search_strategy</a>).
         </description>
         <examples>
            <example>optimization_ex.cpp.html</example>
         </examples>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>find_min_single_variable</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_line_search_abstract.h</spec_file>
         <description>
             Performs a bound constrained minimization of a nonlinear function.  The 
             function must be of a single variable.  Derivatives are not required.  
         </description>
                                 
      </component>

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      <component>
         <name>solve_qp_using_smo</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_solve_qp_using_smo_abstract.h</spec_file>
         <description>
             This function solves the following quadratic program:
<pre>
   Minimize: f(alpha) == 0.5*trans(alpha)*Q*alpha - trans(alpha)*b
   subject to the following constraints:
      sum(alpha) == C 
      min(alpha) >= 0 
</pre>

         </description>
                                 
      </component>

   <!-- ************************************************************************* -->
      
      
      <component>
         <name>find_min_bobyqa</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_bobyqa_abstract.h</spec_file>
         <description>
            This function defines the dlib interface to the BOBYQA software developed by M.J.D Powell.
            BOBYQA is a method for optimizing a function in the absence of derivative information.  
            Powell described it as a method that seeks the least value of a function of many 
            variables, by applying a trust region method that forms quadratic models by 
            interpolation.  There is usually some freedom in the interpolation conditions, 
            which is taken up by minimizing the Frobenius norm of the change to the second 
            derivative of the model, beginning with the zero matrix. The values of the variables 
            are constrained by upper and lower bounds.  

            <p>
            The following paper, published in 2009 by Powell, describes the
            detailed working of the BOBYQA algorithm.  

               <blockquote>
               The BOBYQA algorithm for bound constrained optimization 
               without derivatives by M.J.D. Powell
               </blockquote>
            </p>

            <p>
               Note that BOBYQA only works on functions of two or more variables.  So if you need to perform 
               derivative-free optimization on a function of a single variable 
               then you should use the <a href="#find_min_single_variable">find_min_single_variable</a>
               function.
            </p>

         </description>
         <examples>
            <example>optimization_ex.cpp.html</example>
            <example>model_selection_ex.cpp.html</example>
         </examples>
                                 
      </component>

   <!-- ************************************************************************* -->
      
      <component>
         <name>find_max_bobyqa</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_bobyqa_abstract.h</spec_file>
         <description>
            This function is identical to the <a href="#find_min_bobyqa">find_min_bobyqa</a> routine 
            except that it negates the objective function before performing optimization.  
            Thus this function will attempt to find the maximizer of the objective rather than 
            the minimizer.
            <p>
               Note that BOBYQA only works on functions of two or more variables.  So if you need to perform 
               derivative-free optimization on a function of a single variable 
               then you should use the <a href="#find_max_single_variable">find_max_single_variable</a>
               function.
            </p>
         </description>
         <examples>
            <example>optimization_ex.cpp.html</example>
            <example>model_selection_ex.cpp.html</example>
         </examples>
                                 
      </component>

   <!-- ************************************************************************* -->
      
      <component>
         <name>find_min_using_approximate_derivatives</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_abstract.h</spec_file>
         <description>
             Performs an unconstrained minimization of a nonlinear function using 
             some search strategy (e.g. <a href="#bfgs_search_strategy">bfgs_search_strategy</a>).
             This version doesn't take a gradient function but instead numerically approximates 
             the gradient.
         </description>
         <examples>
            <example>optimization_ex.cpp.html</example>
         </examples>
                                 
      </component>

   <!-- ************************************************************************* -->
      
      <component>
         <name>find_max</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_abstract.h</spec_file>
         <description>
             Performs an unconstrained maximization of a nonlinear function using 
             some search strategy (e.g. <a href="#bfgs_search_strategy">bfgs_search_strategy</a>).
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->
      
      <component>
         <name>find_max_single_variable</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_line_search_abstract.h</spec_file>
         <description>
             Performs a bound constrained maximization of a nonlinear function.  The 
             function must be of a single variable.  Derivatives are not required.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->
      
      <component>
         <name>find_max_using_approximate_derivatives</name>
         <file>dlib/optimization.h</file>
         <spec_file link="true">dlib/optimization/optimization_abstract.h</spec_file>
         <description>
             Performs an unconstrained maximization of a nonlinear function using 
             some search strategy (e.g. <a href="#bfgs_search_strategy">bfgs_search_strategy</a>).
             This version doesn't take a gradient function but instead numerically approximates 
             the gradient.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->
      
      <component checked="true">
         <name>bigint</name>
         <file>dlib/bigint.h</file>
         <spec_file>dlib/bigint/bigint_kernel_abstract.h</spec_file>
         <description>
            This object represents an arbitrary precision unsigned integer.  It's pretty simple.  
            It's interface is just like a normal int, you don't have to tell it how much memory
            to use or anything unusual.  It just goes :)       
         </description>
         
         <implementations>
            <implementation>
               <name>bigint_kernel_1</name>
               <file>dlib/bigint/bigint_kernel_1.h</file>
               <description> 
                  This implementation is done using an array of unsigned shorts.  It is also reference counted.  
                  For further details see the above link.  Also note that kernel_2 should be 
      faster in almost every case so you should really just use that version of the bigint object.
               </description> 
    
               <typedefs>
                  <typedef>
                     <name>kernel_1a</name>
                     <description>is a typedef for bigint_kernel_1</description>
                  </typedef>
               </typedefs>                
               
            </implementation> 
                     
            <implementation>
               <name>bigint_kernel_2</name>
               <file>dlib/bigint/bigint_kernel_2.h</file>
               <description> 
                  This implementation is basically the same as kernel_1 except it uses the 
                  Fast Fourier Transform to perform multiplications much faster.  
               </description> 
    
               <typedefs>
                  <typedef>
                     <name>kernel_2a</name>
                     <description>is a typedef for bigint_kernel_2</description>
                  </typedef>
               </typedefs>                
               
            </implementation> 
                     
         </implementations>
                           
                        
      </component>
      
   <!-- ************************************************************************* -->
      
      <component>
         <name>crc32</name>
         <file>dlib/crc32.h</file>
         <spec_file>dlib/crc32/crc32_kernel_abstract.h</spec_file>
         <description>
            This object represents the CRC-32 algorithm for calculating
                        checksums.   
         </description>
         
         <implementations>
            <implementation>
               <name>crc32_kernel_1</name>
               <file>dlib/crc32/crc32_kernel_1.h</file>
               <description> 
                  This implementation uses the polynomial 0xedb88320. 
               </description> 
    
               <typedefs>
                  <typedef>
                     <name>kernel_1a</name>
                     <description>is a typedef for crc32_kernel_1</description>
                  </typedef>
               </typedefs>                
               
            </implementation>                                  
         </implementations>
                        
      </component>
            
   <!-- ************************************************************************* -->
      
      <component>
         <name>rand</name>
         <file>dlib/rand.h</file>
         <spec_file>dlib/rand/rand_kernel_abstract.h</spec_file>
         <description>
            This object represents a pseudorandom number generator.
         </description>
         
         <implementations>
            <implementation>
               <name>rand_kernel_1</name>
               <file>dlib/rand/rand_kernel_1.h</file>
               <description> 
                  This implementation is done using the Mersenne Twister algorithm.
               </description> 
    
               <typedefs>
                  <typedef>
                     <name>kernel_1a</name>
                     <description>is a typedef for rand_kernel_1</description>
                  </typedef>
               </typedefs>                
               
            </implementation> 
                     
         </implementations>
         
         <extensions>
      
            <extension>
               <name>rand_float</name>
               <spec_file>dlib/rand/rand_float_abstract.h</spec_file>
               <description> 
                  This extension gives rand the ability to generate random floating point numbers.
               </description> 

               <implementations>
                  <implementation>
                     <name>rand_float_1</name>
                     <file>dlib/rand/rand_float_1.h</file>
                     <description> 
                        The implementation is obvious.  Click on the link if you want to see.                        
                     </description> 

                     <typedefs>
                        <typedef>
                           <name>float_1a</name>
                           <description>is a typedef for rand_kernel_1a extended by rand_float_1</description>
                        </typedef>
                     </typedefs>                
                     
                  </implementation> 
                           
               </implementations>
   
               
            </extension>
         </extensions>
               
                        
      </component>
            
   <!-- ************************************************************************* -->
      
      <component>
         <name>rectangle</name>
         <file>dlib/geometry.h</file>
         <spec_file>dlib/geometry/rectangle_abstract.h</spec_file>
         <description>
            This object represents a rectangular region inside a Cartesian 
            coordinate system.  It allows you to easily represent and manipulate
            rectangles.
         </description>
      </component>
            
   <!-- ************************************************************************* -->
      
      <component>
         <name>vector</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/vector_abstract.h</spec_file>
         <description>
            This object represents a two or three dimensional vector.
         </description>
      </component>
      
   <!-- ************************************************************************* -->
      
      <component>
         <name>point</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/vector_abstract.h</spec_file>
         <description>
               This object represents a point inside a Cartesian coordinate system.
         </description>
      </component>
      
   <!-- ************************************************************************* -->
      
      <component>
         <name>running_stats</name>
         <file>dlib/statistics.h</file>
         <spec_file link="true">dlib/statistics/statistics_abstract.h</spec_file>
         <description>
                This object represents something that can compute the running mean and
                variance of a stream of real numbers.  
         </description>

         <examples>
            <example>kcentroid_ex.cpp.html</example>
         </examples>
                                 
      </component>
      
      
   <!-- ************************************************************************* -->

      <component>
         <name>running_covariance</name>
         <file>dlib/statistics.h</file>
         <spec_file link="true">dlib/statistics/statistics_abstract.h</spec_file>
         <description>
                This object is a simple tool for computing the mean and
                covariance of a sequence of vectors.  
         </description>

      </component>
      
      
   <!-- ************************************************************************* -->

      <component>
         <name>random_subset_selector</name>
         <file>dlib/statistics.h</file>
         <spec_file>dlib/statistics/random_subset_selector_abstract.h</spec_file>
         <description>
               This object is a tool to help you select a random subset of a large body of data.  
               In particular, it is useful when the body of data is too large to fit into memory.
         </description>

                                 
      </component>
      
      
   <!-- ************************************************************************* -->

      <component>
         <name>hsort_array</name>
         <file>dlib/sort.h</file>
         <spec_file link="true">dlib/sort.h</spec_file>
         <description>
            hsort_array is an implementation of the heapsort algorithm.  It will sort anything that has an 
            array like operator[] interface.  
         </description>
                                 
      </component>
      
   <!-- ************************************************************************* -->
      
      <component>
         <name>put_in_range</name>
         <file>dlib/algs.h</file>
         <spec_file link="true">dlib/algs.h</spec_file>
         <description>
            This is a simple function that takes a range and a value and returns the given
            value if it is within the range.  If it isn't in the range then it returns the  
            end of range value that is closest.
         </description>
                                 
      </component>
               
   <!-- ************************************************************************* -->
      
      <component>
         <name>isort_array</name>
         <file>dlib/sort.h</file>
         <spec_file link="true">dlib/sort.h</spec_file>
         <description>
            isort_array is an implementation of the insertion sort algorithm.  It will sort anything that has an 
            array like operator[] interface.   
         </description>
                                 
      </component>
               
      
   <!-- ************************************************************************* -->
      
      <component>
         <name>qsort_array</name>
         <file>dlib/sort.h</file>
         <spec_file link="true">dlib/sort.h</spec_file>
         <description>
            qsort_array is an implementation of the QuickSort algorithm.  It will sort anything that has an array like 
            operator[] interface.  If the quick sort becomes unstable then it switches to a heap sort.  This 
            way sorting is guaranteed to take at most N*log(N) time.
         </description>
                                 
      </component>
            
      
   <!-- ************************************************************************* -->
      
      <component>
         <name>md5</name>
         <file>dlib/md5.h</file>
         <spec_file>dlib/md5/md5_kernel_abstract.h</spec_file>
         <description>
            This is an implementation of The MD5 Message-Digest Algorithm as described in rfc1321.   
         </description>
                                 
      </component>
            
      
      
   <!-- ************************************************************************* -->
      
      <component>
         <name>median</name>
         <file>dlib/algs.h</file>
         <spec_file link="true">dlib/algs.h</spec_file>
         <description>
            This function takes three parameters and finds the median of the three.  The median is swapped into
            the first parameter and the first parameter ends up in one of the other two, unless the first parameter was
            the median to begin with of course. 
         </description>
                                 
      </component>
            
   <!-- ************************************************************************* -->
      
      <component>
         <name>square_root</name>
         <file>dlib/algs.h</file>
         <spec_file link="true">dlib/algs.h</spec_file>
         <description>        
            square_root is a function which takes an unsigned long and returns the square root of it or
            if the root is not an integer then it is rounded up to the next integer.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>edge</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a <a href="containers.html#graph">graph</a> object and a 
            pair of indices.  It returns a reference to the edge object between the two nodes
            with the given indices. 
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>is_join_tree</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes two <a href="containers.html#graph">graph</a> objects and
            checks if the second of the two graphs is a valid join tree (aka tree decomposition)
            of the first graph.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>create_join_tree</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a <a href="containers.html#graph">graph</a> object and
            creates a join tree for that graph.  Or in other words, this function finds a 
            tree decomposition of the given graph.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>graph_contains_directed_cycle</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function checks a <a href="containers.html#directed_graph">directed_graph</a> for directed cycles.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>set_intersection</name>
         <file>dlib/set_utils.h</file>
         <spec_file link="true">dlib/set_utils/set_utils_abstract.h</spec_file>
         <description>        
            This function takes two <a href="containers.html#set">set</a> objects and 
            gives you their intersection.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>set_union</name>
         <file>dlib/set_utils.h</file>
         <spec_file link="true">dlib/set_utils/set_utils_abstract.h</spec_file>
         <description>        
            This function takes two <a href="containers.html#set">set</a> objects and 
            gives you their union.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>set_difference</name>
         <file>dlib/set_utils.h</file>
         <spec_file link="true">dlib/set_utils/set_utils_abstract.h</spec_file>
         <description>        
            This function takes two <a href="containers.html#set">set</a> objects and 
            gives you their difference.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>set_intersection_size</name>
         <file>dlib/set_utils.h</file>
         <spec_file link="true">dlib/set_utils/set_utils_abstract.h</spec_file>
         <description>        
            This function takes two <a href="containers.html#set">set</a> objects and tells you
            how many items they have in common.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>triangulate_graph_and_find_cliques</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a <a href="containers.html#graph">graph</a> and
            turns it into a chordal graph.  It also returns a 
            <a href="containers.html#set">set</a> that contains
            all the cliques present in the chordal graph.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>create_moral_graph</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a <a href="containers.html#directed_graph">directed_graph</a>
            and returns the moralized version of the graph in the form of a 
            <a href="containers.html#graph">graph</a> object.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>graph_contains_length_one_cycle</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a <a href="containers.html#graph">graph</a>
            or <a href="containers.html#directed_graph">directed_graph</a> object and
            returns true if and only if the graph contains a node that has an edge that
            links back to itself.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>find_connected_nodes</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a node from a <a href="containers.html#graph">graph</a>
            or <a href="containers.html#directed_graph">directed_graph</a> object and a 
            <a href="containers.html#set">set</a> of unsigned longs.  It finds all the
            nodes in the given graph that are connected to the given node by an 
            undirected path and returns them in the set (also note that the
            original query node is also returned in this set).
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>graph_is_connected</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a <a href="containers.html#graph">graph</a> or
            <a href="containers.html#directed_graph">directed_graph</a> object and
            determines if the graph is connected.  That is, it returns true if and only if
            there is an undirected path between any two nodes in the given graph.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>is_clique</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a <a href="containers.html#graph">graph</a> and a 
            <a href="containers.html#set">set</a> of node index values and checks 
            if the specified set of nodes is a clique in the graph.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>copy_graph_structure</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a <a href="containers.html#graph">graph</a> or 
            <a href="containers.html#directed_graph">directed_graph</a> and copies  
            its structure to another graph or directed_graph object.  The only 
            restriction is that you can't copy the structure of a graph into a
            directed_graph.  The three other possible combinations are allowed
            however.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>is_maximal_clique</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function takes a <a href="containers.html#graph">graph</a> and a 
            <a href="containers.html#set">set</a> of node index values and checks 
            if the specified set of nodes is a maximal clique in the graph.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>nearest_point</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            This function takes a <a href="#rectangle">rectangle</a> and a 
            <a href="#point">point</a> and returns the point in the given 
            rectangle that is nearest to the given point.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>move_rect</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            This function takes a <a href="#rectangle">rectangle</a> and moves
            it so that it's upper left corner occupies the given location.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>resize_rect_height</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            This function takes a <a href="#rectangle">rectangle</a> and 
            returns a new rectangle with the given height but otherwise with the 
            same edge points as the original rectangle. 
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>resize_rect_width</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            This function takes a <a href="#rectangle">rectangle</a> and 
            returns a new rectangle with the given width but otherwise with the 
            same edge points as the original rectangle. 
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>resize_rect</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            This function takes a <a href="#rectangle">rectangle</a> and 
            returns a new rectangle with the given size but with the same upper
            left corner as the original rectangle.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>translate_rect</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            This function takes a <a href="#rectangle">rectangle</a> and moves
            it by a given number of units along the x and y axis relative to
            where it was before the move.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>quantum_register</name>
         <file>dlib/quantum_computing.h</file>
         <spec_file link="true">dlib/quantum_computing/quantum_computing_abstract.h</spec_file>
         <description>        
                This object represents a set of quantum bits.  It can be used
                with the quantum <a href="#gate">gate</a> object to simulate
                quantum algorithms.
         </description>

         <examples>
            <example>quantum_computing_ex.cpp.html</example>
         </examples>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>gate</name>
         <file>dlib/quantum_computing.h</file>
         <spec_file link="true">dlib/quantum_computing/quantum_computing_abstract.h</spec_file>
         <description>        
            This object represents a quantum gate that operates on a 
            <a href="#quantum_register">quantum_register</a>.   
         </description>
         <examples>
            <example>quantum_computing_ex.cpp.html</example>
         </examples>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>centered_rect</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            There are various overloads of this function but the basic idea is
            that it returns a <a href="#rectangle">rectangle</a> with a given 
            width and height and centered about a given point.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>shrink_rect</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            This function takes a <a href="#rectangle">rectangle</a> object, 
            shrinks its borders by a given amount, and returns the result.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>grow_rect</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            This function takes a <a href="#rectangle">rectangle</a> object, 
            grows its borders by a given amount, and returns the result.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>rotate_point</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/vector_abstract.h</spec_file>
         <description>        
            This is a function that rotates a 2D <a href="#vector">vector</a> or 
            <a href="#point">point</a> object about a given point.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>point_rotator</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/vector_abstract.h</spec_file>
         <description>        
            This is an object that rotates a 2D <a href="#vector">vector</a> or 
            <a href="#point">point</a> object about the origin.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>get_rect</name>
         <file>dlib/geometry.h</file>
         <spec_file link="true">dlib/geometry/rectangle_abstract.h</spec_file>
         <description>        
            This is a simple template function that returns a rectangle 
            representing the size of a 2D container (e.g. <a href="containers.html#matrix">matrix</a> or
            <a href="containers.html#array2d">array2d</a>). 
         </description>
      </component>

   <!-- ************************************************************************* -->

      <component>
         <name>graph_contains_undirected_cycle</name>
         <file>dlib/graph_utils.h</file>
         <spec_file link="true">dlib/graph_utils/graph_utils_abstract.h</spec_file>
         <description>        
            This function checks a <a href="containers.html#directed_graph">directed_graph</a> for undirected cycles.
         </description>
                                 
      </component>

   <!-- ************************************************************************* -->

   </components>

   <!-- ************************************************************************* -->


</doc>

