jvx.numeric
Class PnEnergy

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

All Implemented Interfaces:

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

Direct Known Subclasses:

PnAreaEnergy, PnConfEnergy, PnDiriEnergy, PnSpringEnergy

public abstract class PnEnergy

extends PnFunction

Energy functional on triangulated surfaces including gradient and hessian computations.

Surface must contain all boundary information. Domain is only used by some energy functionals to compute the stiffness matrix.

Version:

04.01.01, 2.50 revised (kp) Domain geometry may be missing.
06.06.99, 2.00 revised (kp) Extracted from merged PnAreaEnergy and PnDirichletEnergy.
21.04.99, 1.00 created (kp) from PnDiriEnergy.

Author:

Konrad Polthier

See Also:

Serialized Form

Field Summary

protected PgBndPolygon[]	m_bndList Array of boundary curves.
protected boolean	m_bNormal Restrict gradient to normal component.
protected boolean	m_bTangential Restrict gradient to tangential component.
protected int	m_dim Dimension of vertices in image triangulation.
protected PgElementSet	m_domain Domain of map, or null.
protected int[]	m_index For each interior vertex this index array stores its position in the global vertex array.
protected int[]	m_invIndex For each regular vertex this index array stores either a -1 or its position in the interior vertex array m_index.
protected int	m_noiv Number of free vertices, determines number of free variables = m_noiv*m_dim.
protected int	m_nop Number of vertices in triangulation.
protected PnStiffMatrix	m_stiffMatrix Stiffness matrix.
protected PdVector	m_store Vector for intermediate storage.
protected PgElementSet	m_surface Surface or image of map.

Fields inherited from class jvx.numeric.PnFunction

m_bEvaluable

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

PnEnergy()

Method Summary

double	eval(PdVector coord) Compute Area energy of a coord vector using the stiffness matrix of a PnArea instance.
PdVector	evalGradient(PdVector coord, PdVector gradient) Evaluate Area gradient of a coord vector using the stiffness matrix of a PnArea instance.
abstract PdMatrix	evalHessian(PdMatrix hessian) Subclass must supply method to compute hessian of energy.
int	getNumOfVariables() Get number of free variables of energy.
PdVector[]	getSpectrum(PdVector eValue, PdVector[] eVector) Compute eigenvalues and eigenvectors of normalized hessian.
void	init() If instance has missing name then assign default name 'object_NUMBER' where number is the total number of already created instances.
void	initSurface(PgElementSet domain, PgElementSet surface) Method called from energyMinimizer.minimizeStep() to update the stiffness matrix after conjugate gradient method has returned.
boolean	setSurface(PgElementSet domain, PgElementSet surface) Set domain and surface, and initialize energy structure.
void	testEigenvalues()

Methods inherited from class jvx.numeric.PnFunction

enableEvaluation, isEvaluable

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, update, updatePanels

Methods inherited from class java.lang.Object

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

Field Detail

m_domain

protected PgElementSet m_domain

Domain of map, or null.

m_surface

protected PgElementSet m_surface

Surface or image of map.

m_nop

protected int m_nop

Number of vertices in triangulation.

m_noiv

protected int m_noiv

Number of free vertices, determines number of free variables = m_noiv*m_dim.

m_dim

protected int m_dim

Dimension of vertices in image triangulation.

m_stiffMatrix

protected PnStiffMatrix m_stiffMatrix

Stiffness matrix.

m_bndList

protected PgBndPolygon[] m_bndList

Array of boundary curves.

m_store

protected PdVector m_store

Vector for intermediate storage.

m_bTangential

protected boolean m_bTangential

Restrict gradient to tangential component.

m_bNormal

protected boolean m_bNormal

Restrict gradient to normal component.

m_index

protected int[] m_index

For each interior vertex this index array stores its position in the global vertex array. Length of array is equal to number of interior vertices.

m_invIndex

protected int[] m_invIndex

For each regular vertex this index array stores either a -1 or its position in the interior vertex array m_index. Length of array is equal to number of regular vertices.

Constructor Detail

PnEnergy

public PnEnergy()

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

initSurface

public void initSurface(PgElementSet domain,
                        PgElementSet surface)

Method called from energyMinimizer.minimizeStep() to update the stiffness matrix after conjugate gradient method has returned. E.g. PnDiriEnergy should copy surface into domain if in iteration mode i.e. if dimension of domain and surface are equal.

getNumOfVariables

public int getNumOfVariables()

Get number of free variables of energy.

Overrides:

getNumOfVariables in class PnFunction

setSurface

public boolean setSurface(PgElementSet domain,
                          PgElementSet surface)

Set domain and surface, and initialize energy structure. Method is called from outside whenever domain or surface has been updated. Domain argument maybe null.

eval

public double eval(PdVector coord)

Compute Area energy of a coord vector using the stiffness matrix of a PnArea instance. Method uses the array m_store of PnArea for intermediate storage and modifies its entries.

Overrides:

eval in class PnFunction

Parameters:

coord - Coordinate vector with list of doubles

Returns:

double Energy of coordinate vector

See Also:

vgp.discrete.harmonic.PnAreaEnergy

evalGradient

public PdVector evalGradient(PdVector coord,
                             PdVector gradient)

Evaluate Area gradient of a coord vector using the stiffness matrix of a PnArea instance. Along boundary gradient is modified to fulfill any boundary constraints. Special feature for outside calls: If outside wants to evaluate the gradient without allocating gradient, then instead of gradient a null may be passed. In this case the gradient information is store in an internal variable which is returned as gradient. Handle with care and do not modify size returned gradient.

Overrides:

evalGradient in class PnFunction

Parameters:

coord - Coordinate vector with list of doubles

gradient - Gradient vector to be modified, maybe null.

See Also:

vgp.discrete.harmonic.PnAreaEnergy

evalHessian

public abstract PdMatrix evalHessian(PdMatrix hessian)

Subclass must supply method to compute hessian of energy.

Overrides:

evalHessian in class PnFunction

Parameters:

hessian - Hessian of energy with square size

getSpectrum

public PdVector[] getSpectrum(PdVector eValue,
                              PdVector[] eVector)

Compute eigenvalues and eigenvectors of normalized hessian.

Parameters:

eValue - Vector to store the eigenvalues. Size will be adjusted.

eVector - Possibly empty array to store the eigenvectors. Will be returned.

testEigenvalues

public void testEigenvalues()