jvx.numeric
Class PnEnergyMinimizer

java.lang.Object
  |
  +--jv.object.PsObject
        |
        +--jvx.numeric.PnEnergyMinimizer

All Implemented Interfaces:

java.lang.Cloneable, PsUpdateIf, java.lang.Runnable, java.io.Serializable

public class PnEnergyMinimizer

extends PsObject

implements java.lang.Runnable

Main class to vary a surface to minimize a given energy functional. Minimization runs in a separate thread. For Dirichlet and Area minimization support for hessian and eigenvalues included.

Version:

04.01.01, 1.50 revised (kp) Domain geometry may be missing.
08.11.00, 2.10 revised (kp) Replace formatting with PuString rather than Fmt.
21.07.99, 2.00 revised (kp)
00.00.98, 1.00 created (kp)

Author:

Konrad Polthier

See Also:

Serialized Form

Field Summary

static int	AREA
static int	CONFORMAL
static int	DIRICHLET
protected boolean	m_bHessianIsL2Normalized Flag whether hessian matrix is normalized with inverse of L2 matrix.
protected boolean	m_bRunning Flag used to indicate that thread should stop.
protected boolean	m_bUpdateDomain Flag whether domain is updated after each CG-minization loop.
protected boolean	m_bUpdateNormals Flag whether surface normals are updated after each minimization loop.
protected double	m_cgEps Accuracy criteria used to terminate CG iterations.
protected PnConjugateGradient	m_cgMethod Conjugate Gradient Method.
protected PdVector	m_coord Coordinate vector.
protected int	m_currLoop Current loops in CG algorithm, used in infoPanel.
protected PgElementSet	m_domain Optional domain surface used for minimizing energies related to maps between surfaces.
protected PnEnergy	m_energy Function computing some energy, its gradient and hessian.
protected PdVector	m_eValue Vector with eigenvalues.
protected PdVector[]	m_eVector Array with eigenvectors.
protected int[]	m_evSortInd Index vector listing eigenvalues by size.
protected double	m_finalEnergy Energy after minimization, used in infoPanel.
protected PdMatrix	m_hessian Hessian matrix.
protected double	m_initialEnergy Initial energy, used in infoPanel.
protected int	m_numIterations Number of used iterations in last CG algorithm, used in infoPanel.
protected int	m_numLoops Number of loops, i.e. number of calls to CG algorithm, used in infoPanel.
protected PgElementSet	m_surface Surface which will be modified.
protected java.lang.Thread	m_thread Thread running during minimization.
protected PgVectorField	m_vf Vector field for display of gradient and eigenvectors.
static int	SPRING

Fields inherited from class jv.object.PsObject

HAS_CONFIG_PANEL, HAS_INFO_PANEL, HAS_MATERIAL_PANEL, INSPECTOR_INFO, INSPECTOR_INFO_EXT, IS_DELETED, IS_FIXED, IS_SELECTED, IS_USED, m_infoPanel, m_name, m_panelList, m_parent, m_tag, m_updateList, NUM_TAGS

Constructor Summary

PnEnergyMinimizer()

Method Summary

void	computeEigenvectors()
void	enableUpdateDomain(boolean flag) Flag whether domain is updated after each CG-minization loop.
PgElementSet	getDomain()
PnEnergy	getEnergy() Get current energy.
PgElementSet	getSurface()
void	init() If instance has missing name then assign default name 'object_NUMBER' where number is the total number of already created instances.
boolean	isRunning() Check whether energy minimizer is currently running a minimization process.
double	minimize() Minimize energy by invoking conjugate gradient method in a loop.
void	printEigenvalues()
void	printEigenvectors()
void	printGradient()
void	printHessian()
void	run() Do energy minimization until m_numLoops are done or until a call of stop().
void	setEnergy(PnEnergy energy) Set new energy and clear all vector fields.
void	setNumLoops(int numLoops) Set number of calls of conjugate gradient method to be performed during each call to PnEnergyMinimizer#minimize().
boolean	setSurface(PgElementSet domain, PgElementSet surface) Set references to domain and image surface.
void	showEigenvector(int ind)
void	showGradient()
void	showNone()
void	start() Start energy minimization in separate thread.
void	step() Move vertices in negative gradient direction as certain amount.
void	stop() Stop energy minimization in separate thread.
boolean	update(java.lang.Object event) Update the class whenever a child has changed.

Methods inherited from class jv.object.PsObject

addInspector, addUpdateListener, clearTag, clone, clone, clone, copy, getFather, getInfoPanel, getInspector, getName, getNumObjects, hasInspector, hasTag, hasUpdateListener, instanceOf, instanceOf, removeInspector, removeUpdateListener, setName, setParent, setTag, toString, updatePanels

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DIRICHLET

public static final int DIRICHLET

AREA

public static final int AREA

CONFORMAL

public static final int CONFORMAL

SPRING

public static final int SPRING

m_domain

protected PgElementSet m_domain

Optional domain surface used for minimizing energies related to maps between surfaces.

m_surface

protected PgElementSet m_surface

Surface which will be modified. Target geometry of maps.

m_vf

protected PgVectorField m_vf

Vector field for display of gradient and eigenvectors. Field is reset to null whenever the number of vertices changes.

m_hessian

protected PdMatrix m_hessian

Hessian matrix.

m_bUpdateNormals

protected boolean m_bUpdateNormals

Flag whether surface normals are updated after each minimization loop.

m_bUpdateDomain

protected boolean m_bUpdateDomain

Flag whether domain is updated after each CG-minization loop. When iteratively computing harmonic maps copy image surface into domain after minimization to update domain metric. Main use is inside Pinkall/Polthier algorithm on computing minimal surfaces by iterating harmonic maps.

m_coord

protected PdVector m_coord

Coordinate vector.

m_cgMethod

protected PnConjugateGradient m_cgMethod

Conjugate Gradient Method.

m_energy

protected PnEnergy m_energy

Function computing some energy, its gradient and hessian.

m_numLoops

protected int m_numLoops

Number of loops, i.e. number of calls to CG algorithm, used in infoPanel.

m_currLoop

protected int m_currLoop

Current loops in CG algorithm, used in infoPanel.

m_cgEps

protected double m_cgEps

Accuracy criteria used to terminate CG iterations.

m_initialEnergy

protected double m_initialEnergy

Initial energy, used in infoPanel.

m_finalEnergy

protected double m_finalEnergy

Energy after minimization, used in infoPanel.

m_numIterations

protected int m_numIterations

Number of used iterations in last CG algorithm, used in infoPanel.

m_thread

protected java.lang.Thread m_thread

Thread running during minimization.

m_eVector

protected PdVector[] m_eVector

Array with eigenvectors.

m_eValue

protected PdVector m_eValue

Vector with eigenvalues.

m_evSortInd

protected int[] m_evSortInd

Index vector listing eigenvalues by size.

m_bHessianIsL2Normalized

protected boolean m_bHessianIsL2Normalized

Flag whether hessian matrix is normalized with inverse of L2 matrix.

m_bRunning

protected boolean m_bRunning

Flag used to indicate that thread should stop.

Constructor Detail

PnEnergyMinimizer

public PnEnergyMinimizer()

Method Detail

init

public void init()

Description copied from class: PsObject

If instance has missing name then assign default name 'object_NUMBER' where number is the total number of already created instances.

Overrides:

init in class PsObject

update

public boolean update(java.lang.Object event)

Update the class whenever a child has changed. Method is usually invoked from the children.

Overrides:

update in class PsObject

Following copied from class: jv.object.PsObject

See Also:

PsObject.setParent(PsUpdateIf), PsObject.getFather(), PsObject.addUpdateListener(PsUpdateIf)

getEnergy

public PnEnergy getEnergy()

Get current energy.

setEnergy

public void setEnergy(PnEnergy energy)

Set new energy and clear all vector fields. Domain argument maybe null.

enableUpdateDomain

public void enableUpdateDomain(boolean flag)

Flag whether domain is updated after each CG-minization loop. When iteratively computing harmonic maps copy image surface into domain after minimization to update domain metric. Main use is inside Pinkall/Polthier algorithm on computing minimal surfaces by iterating harmonic maps.

getDomain

public PgElementSet getDomain()

getSurface

public PgElementSet getSurface()

setSurface

public boolean setSurface(PgElementSet domain,
                          PgElementSet surface)

Set references to domain and image surface. Image surface is usually being minimized while domain surface is often used when minimizing energy of maps between surfaces. Dimension of vertices of domain and surface may be different, e.g., domain may have 2-dimensional and surface may have 1-dimensional vertices.

Remark: If the geometries are changed outside this energy minimizer, the user must call setSurface() again to update the energy minimizer. Otherwise, further minimization calls will use the old geometry information.

setNumLoops

public void setNumLoops(int numLoops)

Set number of calls of conjugate gradient method to be performed during each call to PnEnergyMinimizer#minimize().

This number of loops is independent of the number of iterations used in each single invocation of the CG-method, which depends on the requested accurracy PnEnergyMinimizer#m_cgEps.

See Also:

minimize()

minimize

public double minimize()

Minimize energy by invoking conjugate gradient method in a loop. A separate thread is started which calls in each step a conjugate gradient method. The number of loops may be set using #setNumLoops(int).

See Also:

setNumLoops(int)

step

public void step()

Move vertices in negative gradient direction as certain amount. Amount is gradient*h with h=0.01*numLoops.

printGradient

public void printGradient()

showNone

public void showNone()

showGradient

public void showGradient()

printHessian

public void printHessian()

computeEigenvectors

public void computeEigenvectors()

printEigenvalues

public void printEigenvalues()

printEigenvectors

public void printEigenvectors()

showEigenvector

public void showEigenvector(int ind)

isRunning

public boolean isRunning()

Check whether energy minimizer is currently running a minimization process.

start

public void start()

Start energy minimization in separate thread.

stop

public void stop()

Stop energy minimization in separate thread.

run

public void run()

Do energy minimization until m_numLoops are done or until a call of stop().

Specified by:

run in interface java.lang.Runnable