AdaptiveRepulsionData.cpp

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/**
 * Implementation of AdaptiveRepulsionData.
 * @file AdaptiveRepulsionData.cpp
 * @author Ed Bachta
 */

#include "AdaptiveRepulsionData.h"

REGISTER_PARTICLESTUFF(AdaptiveRepulsionData,"Attribute:AdaptiveRepulsionData");

// Witkin-Heckbert recommended values.
#define WH_ALPHA 6.0

int AdaptiveRepulsionData::qlen() { return 6; }

void AdaptiveRepulsionData::getq(double *q)
{
        q[0] = sigma_hat;
        q[1] = sigma_max;
        q[2] = diameter;
        q[3] = alpha;
        q[4] = Ehat;
        q[5] = sdmul;
}

void AdaptiveRepulsionData::setq(double *q)
{
        sigma_hat = q[0];
        sigma_max = q[1];
        diameter = q[2];
        alpha = q[3];
        Ehat = q[4];
        sdmul = q[5];
}

void AdaptiveRepulsionData::qname(char **qn)
{
        qn[0] = "Desired repulsion radius (sigma hat)";
        qn[1] = "Max repulation radius (sigma max)";
        qn[2] = "Expected surface diameter";
        qn[3] = "Repulsion amplitude (alpha)";
        qn[4] = "Desired energy (Ehat)";
        qn[5] = "# of StdDev's away that repul = 0";
}

int AdaptiveRepulsionData::qlenpp()
{
        return 3;
}

void AdaptiveRepulsionData::getqpp(double *q, int i)
{       
        q[0] = r[i];
        q[1] = dr[i];
        q[2] = D[i];
}

void AdaptiveRepulsionData::setqpp(double *q, int i)
{
        r[i] = q[0];
        dr[i] = q[1];
        D[i] = q[2];
}

void AdaptiveRepulsionData::qnamepp(char **qn)
{
        qn[0] = "Repulsion radius (sigma)";
        qn[1] = "Repulsion radius change (sigma dot)";
        qn[2] = "Energy (D)"; 
}

/** Sets the particle system for which the
 * AdaptiveRepulsionData applies.
 * If new_ps is not NULL, then the lengths of internal arrays
 * of particle data are set to the size of the the particle
 * system.
 */
void AdaptiveRepulsionData::setParticleSystem(Particles *new_ps)
{
        ParticleAttribute::setParticleSystem(new_ps);
        if (ps)
        {
                r.resize(ps->size(), 1.0);
                dr.resize(ps->size(), 0.0);
                D.resize(ps->size(), 0.0);
        }
}


/**
 * Attach to a particle system. Sets default constant values and 
 * initializes particle data.
 * @param ps   The owning particle system.
 * @param name The name of this attribute.
 */
AdaptiveRepulsionData::AdaptiveRepulsionData(Particles* ps, std::string name)
  : ParticleAttribute(ps, name)
{
        alpha = WH_ALPHA;
        Ehat = 0.8 * alpha;     
        sdmul = 3.0;
}


/**
 * Callback for particle removal.
 * @param i Index of particle to be removed.
 * @see ParticleAttribute::particleRemoved
 */
void AdaptiveRepulsionData::particleRemoved(unsigned int i)
{

        // Copy end element to ith position
        r[i]  = r.back();
        dr[i] = dr.back();
        D[i]  = D.back();

        // Pop off the end
        r.pop_back();
        dr.pop_back();
        D.pop_back();

}

/** 
 * Callback for particle addition.
 * @param i Index of the particle that has been added.
 */
void AdaptiveRepulsionData::particleAdded(unsigned int i) 
{
        double rad = 1.0;

        r.push_back(rad);
        dr.push_back(0.0);
        D.push_back(0.0);
} 

void AdaptiveRepulsionData::clear()
{
        r.clear();
        dr.clear();
        D.clear();
}

void AdaptiveRepulsionData::integrate(double dt)
{
        for(unsigned int i=0;i<r.size();i++) 
        {
                r[i] += dr[i]*dt;
                // Seems to be more stable if I do not make all of them positive here
                //r[i] = fabs(r[i]);
                //if (r[i] > .5)
                //      r[i] = sigma_max;
                //if (r[i] < -.5)
                //      r[i] = -sigma_max;
        }
}

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