Cleaned up more code and added yet more specs.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403593

dlib/manifold_regularization/graph_creation.h

@@ -9,6 +9,7 @@
 #include "../string.h"
 #include "../rand.h"
 #include <algorithm>
+#include "sample_pair.h"
 
 namespace dlib
 {
@@ -24,8 +25,8 @@ namespace dlib
         ) 
         /*!
             ensures
-                - returns an iterator that points to the element in the given range that has the biggest
-                  distance 
+                - returns an iterator that points to the element in the given range 
+                  that has the biggest distance 
         !*/
         {
             float dist = begin->distance();
@@ -60,13 +61,6 @@ namespace dlib
         const T& random_seed,
         std::vector<sample_pair, alloc>& out
     )
-    /*!
-        requires
-            - samples.size() > 1
-        - 0 < percent <= 1
-        - num > 0
-        - random_seed must be convertible to a string by dlib::cast_to_string()
-    !*/
     {
         std::vector<sample_pair, alloc> edges;
         edges.reserve(num);
@@ -121,11 +115,6 @@ namespace dlib
         const unsigned long k,
         std::vector<sample_pair, alloc>& out
     )
-    /*!
-        requires
-            - samples.size() > k
-        - k > 0
-    !*/
     {
         using namespace impl;
         std::vector<sample_pair> edges;
@@ -188,6 +177,28 @@ namespace dlib
 
     }
 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename alloc
+        >
+    bool contains_duplicate_pairs (
+        const std::vector<sample_pair, alloc>& pairs
+    )
+    {
+        std::vector<sample_pair, alloc> temp(pairs);
+        std::sort(temp.begin(), temp.end(), &order_by_index);
+
+        for (unsigned long i = 1; i < temp.size(); ++i)
+        {
+            // if we found a duplicate
+            if (temp[i-1] == temp[i])
+                return true;
+        }
+
+        return false;
+    }
+
 // ----------------------------------------------------------------------------------------
 
 }

dlib/manifold_regularization/graph_creation_abstract.h

+// Copyright (C) 2010  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_GRAPH_CrEATION_ABSTRACT_H__
+#ifdef DLIB_GRAPH_CrEATION_ABSTRACT_H__
+
+#include <vector>
+#include "../string.h"
+#include "sample_pair_abstract.h"
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename vector_type,
+        typename distance_function_type,
+        typename alloc,
+        typename T
+        >
+    void find_percent_shortest_edges_randomly (
+        const vector_type& samples,
+        const distance_function_type& dist_funct,
+        const double percent,
+        const unsigned long num,
+        const T& random_seed,
+        std::vector<sample_pair, alloc>& out
+    );
+    /*!
+        requires
+            - samples.size() > 1
+            - 0 < percent <= 1
+            - num > 0
+            - random_seed must be convertible to a string by dlib::cast_to_string()
+            - dist_funct(samples[i], samples[j]) must be a valid expression that evaluates
+              to a floating point number
+        ensures
+            - This function randomly samples the space of pairs of integers between
+              0 and samples.size()-1 inclusive.  For each of these pairs, (i,j), a
+              sample_pair is created as follows:    
+                sample_pair(i, j, dist_funct(samples[i], samples[j]))
+              num such sample_pair objects are generated, duplicates are removed, and 
+              then the top percent of them with the smallest distance are stored into 
+              out.  
+            - #out.size() <= num*percent 
+            - contains_duplicate_pairs(#out) == false
+            - for all valid i:
+                - #out[i].distance() == dist_funct(samples[#out[i].index1()], samples[#out[i].index2()])
+            - random_seed is used to seed the random number generator used by this 
+              function.
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename vector_type,
+        typename distance_function_type,
+        typename alloc
+        >
+    void find_k_nearest_neighbors (
+        const vector_type& samples,
+        const distance_function_type& dist_funct,
+        const unsigned long k,
+        std::vector<sample_pair, alloc>& out
+    );
+    /*!
+        requires
+            - samples.size() > k
+            - k > 0
+            - dist_funct(samples[i], samples[j]) must be a valid expression that evaluates
+              to a floating point number
+        ensures
+            - #out == a set of sample_pair objects that represent all the k nearest
+              neighbors in samples according to the given distance function dist_funct.
+            - for all valid i:
+                - #out[i].distance() == dist_funct(samples[#out[i].index1()], samples[#out[i].index2()])
+            - contains_duplicate_pairs(#out) == false
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename alloc
+        >
+    bool contains_duplicate_pairs (
+        const std::vector<sample_pair, alloc>& pairs
+    );
+    /*!
+        ensures
+            - if (pairs contains any elements that are equal according to operator==) then
+                - returns true
+            - else
+                - returns false
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_GRAPH_CrEATION_ABSTRACT_H__
+