SparseVMatrix.cc

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// -*- C++ -*-

// PLearn (A C++ Machine Learning Library)
// Copyright (C) 1998 Pascal Vincent
// Copyright (C) 1999-2001 Pascal Vincent, Yoshua Bengio, Rejean Ducharme and University of Montreal
// Copyright (C) 2002 Pascal Vincent, Julien Keable, Xavier Saint-Mleux
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// 
//  1. Redistributions of source code must retain the above copyright
//     notice, this list of conditions and the following disclaimer.
// 
//  2. Redistributions in binary form must reproduce the above copyright
//     notice, this list of conditions and the following disclaimer in the
//     documentation and/or other materials provided with the distribution.
// 
//  3. The name of the authors may not be used to endorse or promote
//     products derived from this software without specific prior written
//     permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
// NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 
// This file is part of the PLearn library. For more information on the PLearn
// library, go to the PLearn Web site at www.plearn.org


/* *******************************************************      
   * $Id: SparseVMatrix.cc,v 1.6 2004/07/09 19:42:23 tihocan Exp $
   ******************************************************* */

#include "SparseVMatrix.h"

namespace PLearn {
using namespace std;


PLEARN_IMPLEMENT_OBJECT(SparseVMatrix, "ONE LINE DESC", "NO HELP");

SparseVMatrix::SparseVMatrix(const string& filename)
  : nelements(0), positions(0), values(0), rows(0)  
{
  load(filename);
}

SparseVMatrix::SparseVMatrix(VMat m)
  : inherited(m.length(),m.width()), nelements(0), positions(0), values(0), rows(0)
{
  fieldinfos = m->getFieldInfos();                // Copy the field infos
  
  if(m.width()>USHRT_MAX)
    PLERROR("In SparseVMatrix constructor: m.width()=%d can't be greater than USHRT_MAX=%d",m.width(),USHRT_MAX);
  Vec v(m.width());
  real* vptr = v.data();

  // First count nelements
  nelements = 0;
  if(m->hasStats()) // use the stats!
    {
      for(int j=0; j<m.width(); j++)
        {
          const VMFieldStat& st = m->fieldStat(j);
          nelements += st.nmissing() + st.npositive() + st.nnegative();
        }
    }
  else // let's count them ourself
    {
      for(int i=0; i<m.length(); i++)
        {
          m->getRow(i,v);
          for(int j=0; j<v.length(); j++)
            if(vptr[j]!=0.)
              nelements++;
        }
    }
  
  // Now allocate space for those elements
  if(nelements>0)
    {
      positions = new unsigned short[nelements];
      values = new float[nelements];
      int l=length();
      rows = new SparseVMatrixRow[l];
      
      int pos = 0;
      // Fill the representation
      for(int i=0; i<m.length(); i++)
        {
          m->getRow(i,v);
          SparseVMatrixRow& r = rows[i];
          r.row_startpos = pos; 
          int nelem = 0;
          for(int j=0; j<v.length(); j++)
            if(vptr[j]!=0.)
              {
                positions[pos] = j;
                values[pos] = (float)vptr[j];
                pos++;
                nelem++;
              }
          r.nelements = nelem;
        }
    }
}

void
SparseVMatrix::build()
{
    inherited::build();
    build_();
}

void
SparseVMatrix::build_()
{
    // TODO
}

void
SparseVMatrix::declareOptions(OptionList &ol)
{
    inherited::declareOptions(ol);
}

void SparseVMatrix::getNewRow(int i, const Vec& v) const
{
#ifdef BOUNDCHECK
  if(i<0 || i>=length())
    PLERROR("In SparseVMatrix::getNewRow, row number i=%d OUT OF BOUNDS (matrix is %dx%d)",i,length(),width());
  if(v.length()!=width())
    PLERROR("In SparseVMatrix::getNewRow, length of v (%d) is different from width of VMatris (%d)",v.length(),width());
#endif

  if(nelements==0)
    v.clear();
  else
    {      
      SparseVMatrixRow row_i = rows[i];
      float* valueptr =  values + row_i.row_startpos;
      unsigned short* positionptr = positions + row_i.row_startpos;
      int n = row_i.nelements;
  
      real* vdata = v.data();
      
      int j = 0;
      while(n--)
        {
          int nextpos = (int) *positionptr++;
          real nextval = (real) *valueptr++;
          while(j<nextpos)
            vdata[j++] = 0.;
          vdata[j++] = nextval;
        }
      while(j<v.length())
        vdata[j++] = 0.;
    }
}

real SparseVMatrix::dot(int i1, int i2, int inputsize) const
{
#ifdef BOUNDCHECK
  if(i1<0 || i1>=length() || i2<0 || i2>=length() || inputsize>width())
    PLERROR("IN SparseVMatrix::dot OUT OF BOUNDS");
#endif

  if(nelements==0)
    return 0.;
  
  SparseVMatrixRow row_1 = rows[i1];
  float* valueptr_1 =  values + row_1.row_startpos;
  unsigned short* positionptr_1 = positions + row_1.row_startpos;
  int n_1 = row_1.nelements;

  SparseVMatrixRow row_2 = rows[i2];
  float* valueptr_2 =  values + row_2.row_startpos;
  unsigned short* positionptr_2 = positions + row_2.row_startpos;
  int n_2 = row_2.nelements;

  real res = 0.;

  while(n_1 && n_2)
    {
      if(*positionptr_1>=inputsize)
        break;
      if(*positionptr_1==*positionptr_2)
        {
          res += (*valueptr_1)*(*valueptr_2);
          positionptr_1++;
          valueptr_1++;
          n_1--;
          positionptr_2++;
          valueptr_2++;
          n_2--;
        }
      else if(*positionptr_1<*positionptr_2)
        {
          positionptr_1++;
          valueptr_1++;
          n_1--;
        }
      else 
        {
          positionptr_2++;
          valueptr_2++;
          n_2--;
        }
    }

  return res;
}

real SparseVMatrix::dot(int i, const Vec& v) const
{
#ifdef BOUNDCHECK
  if(i<0 || i>=length() || v.length()>width())
    PLERROR("IN SparseVMatrix::dot OUT OF BOUNDS");
#endif

  if(nelements==0)
    return 0.;

  SparseVMatrixRow row_i = rows[i];
  float* valueptr =  values + row_i.row_startpos;
  unsigned short* positionptr = positions + row_i.row_startpos;
  int n = row_i.nelements;
  
  real* vdata = v.data();
  real res = 0.;

  while(n--)
    {
      int nextpos = (int) *positionptr++;
      real nextval = (real) *valueptr++;
      if(nextpos>=v.length())
        break;
      res += nextval*vdata[nextpos];
    }
  return res;
}
/*
void SparseVMatrix::write(ostream& out) const
{
  writeHeader(out,"SparseVMatrix");
  writeField(out,"length",length_);
  writeField(out,"width",width_);
  writeField(out,"fieldinfos",fieldinfos);
  writeField(out,"fieldstats",fieldstats);
  writeField(out,"nelements",nelements);
  write_ushort(out,positions,nelements,false);
  write_float(out,values,nelements,false);
  for(int i=0; i<length(); i++)
    {
      write_int(out,rows[i].nelements);
      write_int(out,rows[i].row_startpos);
    }
  writeFooter(out,"SparseVMatrix");
}

void SparseVMatrix::oldread(istream& in)
{
  readHeader(in,"SparseVMatrix");
  readField(in,"length",length_);
  readField(in,"width",width_);
  readField(in,"fieldinfos",fieldinfos);
  fieldinfos.resize(0); // to fix current bug in setting fieldinfos
  readField(in,"fieldstats",fieldstats);
  
  if(nelements>0)
    {
      delete[] positions;
      delete[] values;
      delete[] rows;
    }
  readField(in,"nelements",nelements);
  positions = new unsigned short[nelements];
  values = new float[nelements];
  rows = new SparseVMatrixRow[length()];
  
  read_ushort(in,positions,nelements,false);
  read_float(in,values,nelements,false);
  for(int i=0; i<length(); i++)
    {
      rows[i].nelements = read_int(in);
      rows[i].row_startpos = read_int(in);
    }
  readFooter(in,"SparseVMatrix");
}
*/
SparseVMatrix::~SparseVMatrix()
{
  if(nelements>0)
    {
      delete[] positions;
      delete[] values;
      delete[] rows;
    }
}


} // end of namespcae PLearn

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