artisynth.core.mechmodels

Class DynamicAttachmentWorker

java.lang.Object

artisynth.core.mechmodels.DynamicAttachmentWorker

public class DynamicAttachmentWorker
extends java.lang.Object

Worker class that applies DynamicAttachments to reduce a dynamic system.

Constructor Summary

Constructors

Constructor and Description
DynamicAttachmentWorker()

Method Summary

Modifier and Type	Method and Description
void	addAttachmentJacobian(DynamicAttachment at, SparseBlockMatrix S, VectorNd f, boolean[] reduced) Reduces the system matrix to account for this attachment.
void	addSolveBlocks(DynamicAttachment at, SparseNumberedBlockMatrix S, boolean[] reduced)
static boolean	containsLoop(DynamicAttachment a, DynamicComponent slave, java.util.HashMap<DynamicComponent,DynamicAttachment> map)
static boolean	containsLoops(java.util.List<DynamicAttachment> list)
java.util.ArrayList<DynamicAttachment>	createOrderedList(java.util.List<DynamicAttachment> list) Orders a list of (possibly interdependent) attachments so that state can be updated correctly by starting at the beginning of the list and running through to the end.
int	getSlaveSolveIndex(DynamicAttachment at)
void	reduceConstraints(DynamicAttachment at, SparseBlockMatrix GT, VectorNd dg, boolean zeroReducedBlocks) Reduces a sparse column matrix (such as the transpose of a constraint matrix) to account for an attachment.
void	reduceRowMatrix(DynamicAttachment at, SparseBlockMatrix G) Reduces a sparse row matrix (such as a constraint matrix) to account for this attachment.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DynamicAttachmentWorker

public DynamicAttachmentWorker()

Method Detail

getSlaveSolveIndex

public int getSlaveSolveIndex(DynamicAttachment at)

reduceConstraints

public void reduceConstraints(DynamicAttachment at,
                              SparseBlockMatrix GT,
                              VectorNd dg,
                              boolean zeroReducedBlocks)

Reduces a sparse column matrix (such as the transpose of a constraint matrix) to account for an attachment. This is done by applying the transform

 GT = P GT
 

where

             T
     [ I -Gka  ]
 P = [         ]
     [ 0   0   ]
 

and Gka is the constraint matrix for this attachment.

Parameters:

at - attachment engendering the reduction

GT - matrix to be reduced

dg - derivative information to be reduced

zeroReducedBlocks - if false, does not zero the blocks in GT associated with the attachment. Although this is not the correct behavior, it can be used in situations where it does not interfere with the final solution and the block contents are used by the attachment for other computations.

reduceRowMatrix

public void reduceRowMatrix(DynamicAttachment at,
                            SparseBlockMatrix G)

Reduces a sparse row matrix (such as a constraint matrix) to account for this attachment. This is done by applying the transform

        T
 G = G P
 

where

             T
     [ I -Gka  ]
 P = [         ]
     [ 0   0   ]
 

and Gka is the constraint matrix for this attachment.

At present, this method requires the matrix G to be vertically linked.

addSolveBlocks

public void addSolveBlocks(DynamicAttachment at,
                           SparseNumberedBlockMatrix S,
                           boolean[] reduced)

addAttachmentJacobian

public void addAttachmentJacobian(DynamicAttachment at,
                                  SparseBlockMatrix S,
                                  VectorNd f,
                                  boolean[] reduced)

Reduces the system matrix to account for this attachment. This is done by applying the transform

          T
 M = P M P
 

where

             T
     [ I -Gka  ]
 P = [         ]
     [ 0   0   ]
 

and Gka is the constraint matrix for this attachment.

createOrderedList

public java.util.ArrayList<DynamicAttachment> createOrderedList(java.util.List<DynamicAttachment> list)

Orders a list of (possibly interdependent) attachments so that state can be updated correctly by starting at the beginning of the list and running through to the end. Unattached components will be at the beginning of the list, and the masters of any given attachment do not depend on any attachments further along the list. This implicitly requires that the attachment configuration does not contain loops.

containsLoops

public static boolean containsLoops(java.util.List<DynamicAttachment> list)

containsLoop

public static boolean containsLoop(DynamicAttachment a,
                                   DynamicComponent slave,
                                   java.util.HashMap<DynamicComponent,DynamicAttachment> map)