CenteredVMatrix.cc

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// -*- C++ -*-

// CenteredVMatrix.cc
//
// Copyright (C) 2004 Olivier Delalleau 
// 
// 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
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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: CenteredVMatrix.cc,v 1.4 2004/07/07 17:30:47 tihocan Exp $ 
   ******************************************************* */

// Authors: Olivier Delalleau

#include "CenteredVMatrix.h"
#include "VMat_maths.h"       

namespace PLearn {
using namespace std;

// CenteredVMatrix //
CenteredVMatrix::CenteredVMatrix()
{
}

CenteredVMatrix::CenteredVMatrix(VMat the_source) {
  this->source = the_source;
  build();
}

PLEARN_IMPLEMENT_OBJECT(CenteredVMatrix,
    "A VMatrix that centers a dataset.",
    "The empirical mean is subtracted to each row of the underlying VMat."
);

// declareOptions //
void CenteredVMatrix::declareOptions(OptionList& ol)
{
  // ### Declare all of this object's options here
  // ### For the "flags" of each option, you should typically specify  
  // ### one of OptionBase::buildoption, OptionBase::learntoption or 
  // ### OptionBase::tuningoption. Another possible flag to be combined with
  // ### is OptionBase::nosave

  // There is no need to save 'mu' since it is recomputed at build time.
  declareOption(ol, "mu", &CenteredVMatrix::mu, OptionBase::nosave,
      "The sample mean");

  // Now call the parent class' declareOptions
  inherited::declareOptions(ol);
}

// build //
void CenteredVMatrix::build()
{
  // ### Nothing to add here, simply calls build_
  inherited::build();
  build_();
}

// build_ //
void CenteredVMatrix::build_()
{
  // ### This method should do the real building of the object,
  // ### according to set 'options', in *any* situation. 
  // ### Typical situations include:
  // ###  - Initial building of an object from a few user-specified options
  // ###  - Building of a "reloaded" object: i.e. from the complete set of all serialised options.
  // ###  - Updating or "re-building" of an object after a few "tuning" options have been modified.
  // ### You should assume that the parent class' build_() has already been called.

  if (source) {
    // Compute the mean.
    computeMean(source, mu);
    setMetaInfoFromSource();
  }
}

// getMu //
Vec CenteredVMatrix::getMu() const {
  return mu;
}

// getNewRow //
void CenteredVMatrix::getNewRow(int i, const Vec& v) const
{
  source->getRow(i, v);
  v -= mu;
}

// makeDeepCopyFromShallowCopy //
void CenteredVMatrix::makeDeepCopyFromShallowCopy(map<const void*, void*>& copies)
{
  inherited::makeDeepCopyFromShallowCopy(copies);

  // ### Call deepCopyField on all "pointer-like" fields 
  // ### that you wish to be deepCopied rather than 
  // ### shallow-copied.
  // ### ex:
  // deepCopyField(trainvec, copies);

  // ### Remove this line when you have fully implemented this method.
  PLERROR("CenteredVMatrix::makeDeepCopyFromShallowCopy not fully (correctly) implemented yet!");
}

} // end of namespace PLearn

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