AutoSDBVMatrix.h

Go to the documentation of this file.

// -*- C++ -*-

// PLearn (A C++ Machine Learning Library)
// Copyright (C) 1998 Pascal Vincent
// Copyright (C) 1999-2002 Pascal Vincent, Yoshua Bengio and University of Montreal
//

// 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,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// 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: AutoSDBVMatrix.h,v 1.9 2004/07/21 16:30:51 chrish42 Exp $
   * AUTHOR: Pascal Vincent
   * This file is part of the PLearn library.
   ******************************************************* */

#ifndef AutoSDBVMatrix_INC
#define AutoSDBVMatrix_INC

//#include "general.h"
#include "SimpleDB.h"
#include <plearn/vmat/VMat.h>
#include <plearn/vmat/RowBufferedVMatrix.h>
//#include <map>

namespace PLearn {
using namespace std;


  //class StringFieldMapping; //fwd decl.

class StringFieldMapping
{
public:

  real dft_val;
  mutable hash_map<string, real> mapping;

  StringFieldMapping()
  {}

  StringFieldMapping(string filename_, real dft_val_= MISSING_VALUE)
    :dft_val(dft_val_), mapping()
  {
    /*ifstream*/ PIFStream f(filename_.c_str());
    while(f)
      {
        string s;
    f >> s;
        //PLearn::read(f, s);
        real val;
    f >> val;
        //PLearn::read(f, val);
        if(f) mapping[s]= val;
      }
  }

  real operator[](const string& s) const
  {
    if(mapping.end() == mapping.find(s))
      return dft_val;
    return mapping[s]; 
  }
 
};


class NumToStringMapping
{
public:

  string filename;
  string dft_val;
  mutable hash_map<real, string> mapping;
  mutable bool loaded;

  NumToStringMapping()
    :loaded(false)
  {}

  NumToStringMapping(string filename_, const string& dft_val_= "")
    :filename(filename_), dft_val(dft_val_), mapping(), loaded(false)
  {}

  void read(istream& in) const
  {
    while(in)
      {
        string s;
        PLearn::read(in, s);
        real val;           
        PLearn::read(in, val);
        if(in) mapping[val]= s;
      }
    loaded= true;
  }

  void load(string filename_= "")
  {
    if(filename_ != "")
      filename= filename_;
    ifstream f(filename.c_str());
    read(f);
  }

  void load() const
  {
    ifstream f(filename.c_str());
    read(f);
  }

  const string& operator[](real x) const
  {
    if(!loaded) load();
    if(mapping.end() == mapping.find(x))
      return dft_val;
    return mapping[x]; 
  }
 
};



class AutoSDBVMatrix: public RowBufferedVMatrix
{
public:
  AutoSDBVMatrix(const string& dbname);


  inline int nstrings() { return sdb_.width() - width(); }
  
  void getMappings();

  virtual string getValString(int col, real val) const
  {
    hash_map<string, NumToStringMapping>::const_iterator it= 
      num2string_map.find(fieldName(col));
    if(it != num2string_map.end())
      return it->second[val];
    return "";
  }

protected:

  virtual void getNewRow(int i, const Vec& v) const;  

  SDB sdb_;
  mutable Row row_;
  hash_map<string, StringFieldMapping> string_field_map;
  hash_map<string, NumToStringMapping> num2string_map;
};





} // end of namespace PLearn

#endif

---