cvrMinimizeBasis.h

Go to the documentation of this file.

/*
 * Copyright (C) 1998-2004
 * Lehrstuhl fuer Technische Informatik, RWTH-Aachen, Germany
 *
 *
 * This file is part of the Computer Vision and Robotics Library (CVR-Lib)
 *
 * The CVR-Lib is free software; you can redistribute it and/or
 * modify it under the terms of the BSD License.
 *
 * All rights reserved.
 *
 * 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. Neither the name of the authors nor the names of its contributors may be
 *    used to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.
 */

/** 
 * \file   cvrMinimizeBasis.h
 *         Contains the template class cvr::minimizeBasis<T>, which generates
 *         a minimum number of basis vectors to approximate a given
 *         set of vectors within a given deviation.
 * \author Thomas Rusert
 * \date   09.06.1999
 *
 * $Id: cvrMinimizeBasis.h,v 1.4 2005/01/07 15:22:18 doerfler Exp $
 */

#ifndef _CVR_MINIMIZE_BASIS_H_
#define _CVR_MINIMIZE_BASIS_H_

#include "cvrMatrix.h"
#include "cvrVector.h"
#include "cvrLinearAlgebraFunctor.h"

namespace cvr {

  /**
   * Functor for the minimization of a basis.
   *
   * This functor generates a minimum number of basis vectors to approximate
   * a given set of vectors within a given deviation.
   *
   * There is a Fast and an Exact method of computing the minimized
   * basis.  Normally the Exact method should be used, because it does
   * not only compute the exact solution and the smallest basis, but
   * may even be faster than the "Fast" method. The "Fast" method is
   * not exact and may return a basis which is larger than
   * necessary.
   *
   * @ingroup gLinearAlgebra
   */
  class minimizeBasis : public linearAlgebraFunctor  {
  public:    
    /** 
     * Enumeration of deviation types 
     */
    enum eDeviationType {Element, /**< the elements of the approximating 
           *   vectors must not deviate more than
           *   maxDeviation */
       Vector,  /**< the l2VectorNorm of deviation vector
           *   between the approximated vector must
           *   not be larger than maxDeviation
           */
       Matrix   /**< the l2MatrixNorm of the difference
           *   matrix between the approximating
           *   and the approximated set of vectors 
           *   must not be larger than maxDeviation
           */
    };

    /**
     * The parameters for the class minimizeBasis
     */
    class parameters : public linearAlgebraFunctor::parameters {
    public:
      /**
       * Default constructor
       */
      parameters();

      /**
       * Copy constructor
       * @param other the parameters object to be copied
       */
      parameters(const parameters& other);

      /**
       * Destructor
       */
      ~parameters();

      /**
       * Copy the contents of a parameters object
       * @param other the parameters object to be copied
       * @return a reference to this parameters object
       */
      parameters& copy(const parameters& other);

      /**
       * Copy the contents of a parameters object
       * @param other the parameters object to be copied
       * @return a reference to this parameters object
       */
      parameters& operator=(const parameters& other);

      /**
       * Returns the name of this class.
       */
      const std::string& name() const;

      /**
       * Returns a pointer to a clone of the parameters
       */
      virtual parameters* clone() const;

      /**
       * Returns a pointer to a new instance of the parameters
       */
      virtual parameters* newInstance() const;

      /**
       * Write the parameters in the given ioHandler
       * @param handler the ioHandler to be used
       * @param complete if true (the default) the enclosing begin/end will
       *        be also written, otherwise only the data block will be written.
       * @return true if write was successful
       */
      virtual bool write(ioHandler& handler,const bool complete=true) const;

      /**
       * Read the parameters from the given ioHandler
       * @param handler the ioHandler to be used
       * @param complete if true (the default) the enclosing begin/end will
       *        be also written, otherwise only the data block will be written.
       * @return true if write was successful
       */
      virtual bool read(ioHandler& handler,const bool complete=true);

      // ------------------------------------------------
      // the parameters
      // ------------------------------------------------
      /**
       * Deviation type
       *
       * Default: Element
       */
      eDeviationType deviationType;
      
      /**
       * Maximal deviation
       *
       * Default: 0.1
       */
      double maxDeviation;
    };

    /**
     * Default constructor
     */
    minimizeBasis();

    /**
     * Construct a functor using the given parameters
     */
    minimizeBasis(const parameters& par);

    /**
     * Copy constructor
     * @param other the object to be copied
     */
    minimizeBasis(const minimizeBasis& other);

    /**
     * Destructor
     */
    virtual ~minimizeBasis();

    /**
     * Operates on the given %parameter.
     *
     * @param testVectors the rows of this matrix
     *        should contain the vectors to be approximated
     * @param newBasis the columns of this matrix 
     *        will contain the new basis vectors
     * @param factors the rows of this matrix will contain
     *        the factors to multiply the new basis vectors
     *        by to approximate the testVectors
     * @return true if apply successful or false otherwise.
     */
    template<typename T>
    bool apply(const matrix<T>& testVectors,
         matrix<T>& newBasis,
         matrix<T>& factors) const;


    /**
     * Copy data of "other" functor.
     * @param other the functor to be copied
     * @return a reference to this functor object
     */
    minimizeBasis& copy(const minimizeBasis& other);

    /**
     * Alias for copy member
     * @param other the functor to be copied
     * @return a reference to this functor object
     */
    minimizeBasis& operator=(const minimizeBasis& other);

    /**
     * Returns the name of this class.
     */
    const std::string& name() const;

    /**
     * Returns a pointer to a clone of this functor.
     */
    virtual minimizeBasis* clone() const;

    /**
     * Returns a pointer to a new instance of this functor.
     */
    virtual minimizeBasis* newInstance() const;

    /**
     * Returns used parameters
     */
    const parameters& getParameters() const;

  protected:
    /**
     * Compute error depending on the given deviation type
     */
    template<typename T>
    T computeError(const eDeviationType& deviation,
                   const matrix<T>& shouldBe,
                   const matrix<T>& current) const;

  };

  /**
   * Read a minimizeBasis<T>::eDeviationType
   *
   * @ingroup gStorable
   */
  bool read(ioHandler& handler,minimizeBasis::eDeviationType& data);

  /**
   * Write a minimizeBasis<T>::eDeviationType
   *
   * @ingroup gStorable
   */
  bool write(ioHandler& handler,const minimizeBasis::eDeviationType& data);

}

#include "cvrMinimizeBasis_template.h"

#endif