Subversion Repositories public iLand

/********************************************************************************************

**    iLand - an individual based forest landscape and disturbance model

**    http://iland.boku.ac.at

**    Copyright (C) 2009-  Werner Rammer, Rupert Seidl

**

**    This program is free software: you can redistribute it and/or modify

**    it under the terms of the GNU General Public License as published by

**    the Free Software Foundation, either version 3 of the License, or

**    (at your option) any later version.

**

**    This program is distributed in the hope that it will be useful,

**    but WITHOUT ANY WARRANTY; without even the implied warranty of

**    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

**    GNU General Public License for more details.

**

**    You should have received a copy of the GNU General Public License

**    along with this program.  If not, see <http://www.gnu.org/licenses/>.

********************************************************************************************/

#ifndef RANDOMTOOLS_H

#define RANDOMTOOLS_H

#include <QtCore/QString>

// RandomIndex: get indicies in a random order

class RandomIndex

{

public:

        RandomIndex(int aCount); ///< creates a index with aCount entries.

        ~RandomIndex();

        bool next(); ///< retrieve next index. return false if all indices used.

        int index() const { return mIndex; } ///< retrieve (random) index

private:

        int mCount;

        int mIndex; ///< currently selected

        char *mField;

        int  mRemaining;

};

class RandomWeighted

{

public:

        RandomWeighted();

        ~RandomWeighted();

        void setup(const int gridSize);

        void setWeight(const int index, const int value);

        int get();

        double getRelWeight(const int index);

        double getRelWeight(const int from, const int to);

private:

        int *mGrid;

        int mSize;

        int mMemorySize;

        int mMaxVal;

        bool mUpdated;

        void updateValues();

};

class Expression;

class RandomCustomPDF

{

public:

        RandomCustomPDF();

        RandomCustomPDF(const QString &densityFunction){ mExpression=0; setup(densityFunction);}

        ~RandomCustomPDF();

        void setup(const QString &funcExpr, const double lowerBound=0., const double upperBound=1., const bool isSumFunc=false, const int stepCount=100);

        // properties

        const QString &densityFunction() const { return mFunction; }

        // operation

        double get(); ///< get a random number

        double getProbOfRange(const double lowerBound, const double upperBound); ///< get probability of random numbers between given bounds.

private:

        QString mFunction;

        RandomWeighted mRandomIndex;

        Expression *mExpression;

        int mSteps;

        double mLowerBound, mUpperBound;

        double mDeltaX;

        bool mSumFunction;

};

#endif // RANDOMTOOLS_H