worm.cpp

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#include "worm.h"
#include "path.h"
 
// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------
// WORM CLASS ----------------------------------------------------------------
// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------
 
/**************************************************************************/
Worm::Worm(int numParticles) {
 
    int numTimeSlices = constants()->numTimeSlices();
 
    /* Setup the bead array */
    beads.resize(numTimeSlices,numParticles);
    beads = 1;
 
    /* Count the initial number of beads */
    resetNumBeadsOn();
 
    /* The initial configuration is always diagonal */
    isConfigDiagonal = true;
 
    /* Max worm cost [PRE 74, 036701 (2006)] */
    maxWormCost = 4.0;
 
    /* Initialize the properties of the worm */
    reset();
}
 
/**************************************************************************/
Worm::~Worm () {
    beads.free();
}
 
/**************************************************************************/
void Worm::reset() {
    gap      = XXX;
    length   = 0;
    sep      = 0.0;
    head     = XXX;
    tail     = XXX;
    special1 = XXX;
    special2 = XXX;
}
 
/**************************************************************************/
void Worm::update(Path &path, const beadLocator &newHead, 
        const beadLocator &newTail) {
 
    /* Assign the new head and tail */
    head = newHead;
    tail = newTail;
 
    /* Compute the new worm gap.  This is defined to be the scalar separation
     * between the head and tail modulo the number of time slices*/
    gap = tail[0] - head[0];
    if (gap < 0)
        gap += path.numTimeSlices;
    PIMC_ASSERT(gap>=0);
 
    /* Get the new length */
    beadLocator beadIndex;
    beadIndex = tail;
    length = 0;
    do {
        ++length;
        beadIndex = path.next(beadIndex);
        /* cout << head[0] << " " << head[1] << " " << tail[0] << " " << tail[1] << " " << beadIndex[0] << " " << beadIndex[1] << endl; */
    } while (!all(beadIndex==head));
 
    /* Now we update the head-tail separation */
    sep = path.getSeparation(tail,head);
 
    /* Unlink the head and tail */
    path.next(head) = XXX;
    path.prev(tail) = XXX;
 
    /* Turn off the special beads */
    special1 = XXX;
    special2 = XXX;
}
 
/**************************************************************************/
double Worm::factor(const beadState state1, const beadLocator &bead2) const {
 
    beadState state2 = getState(bead2);
 
    if ((state1 == NONE) && (state2 == NONE))
        return 1.0;
    else if ((state1 == HEADTAIL) && (state2 == HEADTAIL))
        return 0.0;
    else 
        return 0.5;
}
 
/**************************************************************************/
bool Worm::foundBead(const Path &path, const beadLocator &beadIndex) {
    if (isConfigDiagonal)
        return false;
    else {
        beadLocator beadID;
        beadID = tail;
        while ( (!all(beadID==beadIndex)) && (!all(beadID==path.next(head))) ) {
            beadID = path.next(beadID);
        }
        return all(beadID==beadIndex);
    }
}