Worm Class Reference

Contains information on the worm. More...

#include <worm.h>

Public Member Functions
	Worm (int)
	Constructor. More...
	~Worm ()
	Destructor.
int	beadOn (int, int) const
	Safely get a bead (int indexed)
int	beadOn (const beadLocator &) const
	Safely get a bead (beadLocator indexed)
beadState	getState (const beadLocator &) const
	Get the state of the supplied bead?
double	factor (const beadState, const beadLocator &) const
	Compute the value of the potential action trajectory factor.
double	factor (const beadState state1) const
void	delBead (int, int)
	Safely delete a bead (int indexed)
void	addBead (int, int)
	Safely add a bead (int indexed)
void	delBead (const beadLocator &)
	Safely delete a bead (beadLocator indexed)
void	addBead (const beadLocator &)
	Safely add a bead (beadLocator indexed)
void	reset ()
	Reset the worm to a null state.
void	update (Path &, const beadLocator &, const beadLocator &)
	We update all worm properties for a new head and tail. More...
bool	foundBead (const Path &, const beadLocator &)
	Test to see if a supplied bead is located on a worm.
bool	tooCostly ()
	Return true if the worm is too costly.
bool	tooCostly (const dVec &_sep, int _gap)
	Return true if the worm is too costly.
const Array< unsigned int, 2 > &	getBeads () const
	Return the bead list.
int	getNumBeadsOn () const
	Return the number of active beads.
void	incNumBeadsOn ()
	Increment the number of active beads.
void	decNumBeadsOn ()
	Decrement the number of active beads.
void	resetNumBeadsOn ()
	Reset the number of active beads.

Data Fields
beadLocator	head
	The coordinates of the worm head.
beadLocator	tail
	The coordinates of the worm tail.
beadLocator	special1
	Special bead, used in move updates.
beadLocator	special2
	Special bead, used in move updates.
double	maxWormCost
	The maximum 'cost' of inserting a worm.
dVec	sep
	The spatial separation between head and tail.
int	length
	The length of the worm.
int	gap
	numTimeSlices - length
bool	isConfigDiagonal
	Stores the diagonality of the configuration.

Friends
class	Path
class	PathIntegralMonteCarlo

Detailed Description

Contains information on the worm.

In a grand-canonical or worm simulation, one world line may lose its periodicity in imaginary time. This class holds all parameters and methods used to describe worm configurations.

Definition at line 25 of file worm.h.

Constructor & Destructor Documentation

Worm()

Worm::Worm

(

int

numParticles

)

Constructor.

Initialize the worm object.

Parameters

numParticles

The number of particles

Definition at line 22 of file worm.cpp.

                           {
 
    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();
}

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Member Function Documentation

update()

void Worm::update	(	Path &	path,
		const beadLocator &	newHead,
		const beadLocator &	newTail
	)

We update all worm properties for a new head and tail.

Given new head and tail positions, we assign them and compute the gap, length and separation, while turning off all special flags.

Definition at line 69 of file worm.cpp.

                                    {
 
    /* 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;
}

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The documentation for this class was generated from the following files:

• include/worm.h
• src/worm.cpp