hazardfunctionformationsimple.h

#ifndef HAZARDFUNCTIONFORMATIONSIMPLE_H

#define HAZARDFUNCTIONFORMATIONSIMPLE_H

#include "hazardfunction.h"
#include "person.h"
#include <cmath>

class HazardFunctionFormationSimple : public HazardFunction
{
public:
        HazardFunctionFormationSimple(const Person *pPerson1, const Person *pPerson2, double tr,
                                   double a0, double a1, double a2, double a3, double a4, 
                                   double a5, double Dp, double b);
        ~HazardFunctionFormationSimple();

        double evaluate(double t);
        double calculateInternalTimeInterval(double t0, double dt);
        double solveForRealTimeInterval(double t0, double Tdiff);
private:
        double getLnB() const;
        double getB() const;
        double getC() const;
        double getE(double t0) const;

        const Person *m_pPerson1;
        const Person *m_pPerson2;
        const double m_tr, m_a0, m_a1, m_a2, m_a3, m_a4, m_a5, m_Dp, m_b;
};

inline double HazardFunctionFormationSimple::getLnB() const
{
        double Pi = m_pPerson1->getNumberOfRelationships();
        double Pj = m_pPerson2->getNumberOfRelationships();
        double tBi = m_pPerson1->getDateOfBirth();
        double tBj = m_pPerson2->getDateOfBirth();

        double lnB = m_a0 + m_a1*Pi + m_a2*Pj + m_a3*std::abs(Pi-Pj) - m_a4*(tBi + tBj)/2.0
                   +m_a5*std::abs(-tBi+tBj-m_Dp) - m_b*m_tr;

        return lnB;
}

inline double HazardFunctionFormationSimple::getB() const
{
        return std::exp(getLnB());
}

inline double HazardFunctionFormationSimple::getC() const
{
        double C = m_a4 + m_b;

        return C;
}

inline double HazardFunctionFormationSimple::getE(double t0) const
{
        double Pi = m_pPerson1->getNumberOfRelationships();
        double Pj = m_pPerson2->getNumberOfRelationships();
        double tBi = m_pPerson1->getDateOfBirth();
        double tBj = m_pPerson2->getDateOfBirth();

        double E = std::exp(m_a0 + m_a1*Pi + m_a2*Pj + m_a3*std::abs(Pi-Pj) + m_a4*(t0 - (tBi + tBj)/2.0)
                   +m_a5*std::abs(-tBi+tBj-m_Dp) + m_b*(t0-m_tr));
        return E;
}

#endif // HAZARDFUNCTIONFORMATIONSIMPLE_H