PLearn 0.1
TopNI.h
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00001 // -*- C++ -*-
00002 
00003 // PLearn (A C++ Machine Learning Library)
00004 // Copyright (C) 1998 Pascal Vincent
00005 // Copyright (C) 1999,2000 Pascal Vincent, Yoshua Bengio and University of Montreal
00006 //
00007 
00008 // Redistribution and use in source and binary forms, with or without
00009 // modification, are permitted provided that the following conditions are met:
00010 // 
00011 //  1. Redistributions of source code must retain the above copyright
00012 //     notice, this list of conditions and the following disclaimer.
00013 // 
00014 //  2. Redistributions in binary form must reproduce the above copyright
00015 //     notice, this list of conditions and the following disclaimer in the
00016 //     documentation and/or other materials provided with the distribution.
00017 // 
00018 //  3. The name of the authors may not be used to endorse or promote
00019 //     products derived from this software without specific prior written
00020 //     permission.
00021 // 
00022 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
00023 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00024 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
00025 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00026 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
00027 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00028 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00029 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00030 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00031 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00032 // 
00033 // This file is part of the PLearn library. For more information on the PLearn
00034 // library, go to the PLearn Web site at www.plearn.org
00035 
00036 
00037  
00038 
00039 /* *******************************************************      
00040  * $Id: TopNI.h 8247 2007-11-12 20:22:12Z nouiz $
00041  * AUTHORS: Yoshua Bengio
00042  * This file is part of the PLearn library.
00043  ******************************************************* */
00044 
00045 
00048 #ifndef TopNI_INC
00049 #define TopNI_INC
00050 
00051 #include <plearn/base/general.h>
00052 #include "TMat.h"
00053 
00054 namespace PLearn {
00055 using namespace std;
00056 
00061 template <class T>
00062 class TopNI
00063 {
00064 protected:
00065     int N;
00066     TVec< pair<T,int> > topn;
00067     pair<T,int>* topnptr; 
00068     pair<T,int>* minpair;
00069   
00070 public:
00071 
00073     TopNI()
00074     {}
00075     
00077     TopNI(int the_N) { init(the_N); }
00078 
00080     void init(int the_N)
00081     {
00082         N = the_N;
00083         topn.resize(N); 
00084         topn.resize(0); 
00085         topnptr = topn.data(); 
00086     }
00087 
00088     void reset() { init(N); }
00089 
00091     void update(T value, int index)
00092     {
00093         int l=topn.length();
00094         if(l<N)
00095         {
00096             topn.append( pair<T,int>(value,index) );
00097             if (l==0 || value<minpair->first)
00098                 minpair = &topnptr[l];
00099         }
00100         else if(value>minpair->first)
00101         {
00102             minpair->first = value;
00103             minpair->second = index;
00104 
00106             pair<T,int>* it = topnptr;
00107             int n = N;
00108             while(n--)
00109             {
00110                 if(it->first<minpair->first)
00111                     minpair = it;
00112                 ++it;
00113             }
00114         }
00115     }
00116 
00117     void sort() 
00118     { std::sort(topnptr, topnptr+topn.length(), greater<pair <T,int> >() ); }
00119 
00121     const TVec< pair<T,int> >& getTopN() { return topn; }
00122 };
00123 
00124 } // end of namespace PLearn
00125 
00126 #endif
00127 
00128 
00129 /*
00130   Local Variables:
00131   mode:c++
00132   c-basic-offset:4
00133   c-file-style:"stroustrup"
00134   c-file-offsets:((innamespace . 0)(inline-open . 0))
00135   indent-tabs-mode:nil
00136   fill-column:79
00137   End:
00138 */
00139 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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