PLearn 0.1
BottomNI.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: BottomNI.h 8235 2007-11-07 21:32:01Z nouiz $
00041  * AUTHORS: Yoshua Bengio
00042  * This file is part of the PLearn library.
00043  ******************************************************* */
00044 
00045 
00048 #ifndef BottomNI_INC
00049 #define BottomNI_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 BottomNI
00063 {
00064 protected:
00065     int n_zeros; 
00066     int N;
00067     TVec< pair<T,int> > bottomn;
00068     pair<T,int>* bottomnptr; 
00069     pair<T,int>* maxpair;
00070   
00071 public:
00072 
00074     BottomNI()
00075         : n_zeros(0), N(0), bottomnptr(0), maxpair(0)
00076     { }
00077     
00079     BottomNI(int the_N)
00080         : n_zeros(0), N(0), bottomnptr(0), maxpair(0)
00081     { init(the_N); }
00082 
00084     void init(int the_N)
00085     {
00086         N = the_N;
00087         bottomn.resize(N); 
00088         bottomn.resize(0); 
00089         bottomnptr = bottomn.data(); 
00090         n_zeros=0;
00091     }
00092 
00093     void reset() { init(N); }
00094 
00096     void update(T value, int index)
00097     {
00098         int l=bottomn.length();
00099         if(value==0)
00100             n_zeros++;
00101         if(l<N)
00102         {
00103             bottomn.append( pair<T,int>(value,index) );
00104             if (l==0 || value>maxpair->first)
00105                 maxpair = &bottomnptr[l];
00106         }
00107         else if(value<maxpair->first)
00108         {
00109             maxpair->first = value;
00110             maxpair->second = index;
00111 
00113             pair<T,int>* it = bottomnptr;
00114             int n = N;
00115             while(n--)
00116             {
00117                 if(it->first>maxpair->first)
00118                     maxpair = it;
00119                 ++it;
00120             }
00121         }
00122     }
00123 
00124     int nZeros() const {return n_zeros;}
00125 
00126     void sort() 
00127     { std::sort(bottomnptr, bottomnptr+bottomn.length()); }
00128 
00130     const TVec< pair<T,int> >& getBottomN() { return bottomn; }
00131 };
00132 
00133 } // end of namespace PLearn
00134 
00135 #endif
00136 
00137 
00138 /*
00139   Local Variables:
00140   mode:c++
00141   c-basic-offset:4
00142   c-file-style:"stroustrup"
00143   c-file-offsets:((innamespace . 0)(inline-open . 0))
00144   indent-tabs-mode:nil
00145   fill-column:79
00146   End:
00147 */
00148 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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