cvrUnivariateContinuousDistribution.h

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/*
 * Copyright (C) 2007
 * ITCR, Pablo Alvarado
 *
 *
 * 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
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/**
 * \file   cvrUnivariateContinuousDistribution.h
 *         Contains the class cvr::univariateContinuousDistribution,
 *         parent of all univariate continuous random distributions.
 * \author Pablo Alvarado
 * \date   23.09.2007
 *
 * revisions ..: $Id: cvrUnivariateContinuousDistribution.h,v 1.1 2007/09/26 21:21:52 alvarado Exp $
 */

#ifndef _CVR_UNIVARIATE_CONTINUOUS_DISTRIBUTION_H_
#define _CVR_UNIVARIATE_CONTINUOUS_DISTRIBUTION_H_

#include "cvrRandomDistribution.h"

namespace cvr {

  /**
   * Class univariateContinuousDistribution
   *
   * All univariate continuous distributions return random numbers in a
   * floating point format.  This class establishes the basic interface to
   * allow virtual inheritance of the apply methods.
   *
   * @see univariateContinuousDistribution::parameters.
   *
   * @ingroup gRandomContinuous
   */
  class univariateContinuousDistribution : public randomDistribution {
  public:
    /**
     * Default constructor.
     *
     * Inherited classes can turn off the parameter initialization, since
     * they do the job.
     */
    univariateContinuousDistribution(const bool initParams=true);

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

    /**
     * Copy constructor
     * @param o the object to be copied
     */
    univariateContinuousDistribution(const univariateContinuousDistribution& o);
    /**
     * Destructor
     */
    virtual ~univariateContinuousDistribution();

    /**
     * Get a random number.
     *
     * Returns a random number distributed accordingly to the type of the
     * current instance.
     *
     * The univariateContinuousDistribution can be used to obtain numbers
     * in the interval [0,1).
     *
     * @param rnd float reference where the random number has to be left.
     * @return true if apply successful or false otherwise.
     */
    virtual bool apply(float& rnd);

    /**
     * Get a random number.
     *
     * Returns a random number distributed accordingly to the type of the
     * current instance.
     *
     * The univariateContinuousDistribution can be used to obtain numbers
     * in the interval [0,1).
     *
     * @param rnd double reference where the random number has to be left.
     * @return true if apply successful or false otherwise.
     */
    virtual bool apply(double& rnd);

    /**
     * Get a single precision random number.
     *
     * Returns a random number distributed accordingly to the type of the
     * current instance.
     *
     * The univariateContinuousDistribution can be used to obtain numbers
     * in the interval [0,1).
     *
     * @return a random float number.
     */
    virtual float fdraw();

    /**
     * Get a double precision random number.
     *
     * Returns a random number distributed accordingly to the type of the
     * current instance.
     *
     * The univariateContinuousDistribution can be used to obtain numbers
     * in the interval [0,1).
     *
     * @return a random double number.
     */
    virtual double draw();

    /**
     * Non-virtual method to get a single precision random number.
     *
     * Returns a random number distributed accordingly to the type of the
     * current instance.
     *
     * The univariateContinuousDistribution can be used to obtain numbers
     * in the interval [0,1).
     *
     * @return a random float number.
     */
    float frand();

    /**
     * Non-virtual method to get a double precision random number.
     *
     * Returns a random number distributed accordingly to the type of the
     * current instance.
     *
     * The univariateContinuousDistribution can be used to obtain numbers
     * in the interval [0,1).
     *
     * @return a random double number.
     */
    double rand();


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

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

    /**
     * Returns the complete name of the functor class
     */
    virtual const std::string& name() const;

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

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

    /**
     * Returns used parameters
     */
    bool updateParameters();

  protected:
    /**
     * Float normalizer.
     */
    float fnorm_;

    /**
     * Double normalizer.
     */
    double dnorm_;

  };
}

#endif