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vtkAbstractInterpolatedVelocityField Class Referenceabstract

An abstract class for obtaining the interpolated velocity values at a point. More...

#include <vtkAbstractInterpolatedVelocityField.h>

Inheritance diagram for vtkAbstractInterpolatedVelocityField:
[legend]

Public Types

typedef vtkFunctionSet Superclass
 

Public Member Functions

virtual int IsA (const char *type)
 
vtkAbstractInterpolatedVelocityFieldNewInstance () const
 
void PrintSelf (ostream &os, vtkIndent indent)
 
virtual vtkDataSet * GetLastDataSet ()
 
virtual void SetLastCellId (vtkIdType c, int dataindex)=0
 
void SelectVectors (int fieldAssociation, const char *fieldName)
 
virtual int FunctionValues (double *x, double *f)=0
 
void ClearLastCellId ()
 
virtual void SetCaching (bool)
 
virtual bool GetCaching ()
 
virtual int GetCacheHit ()
 
virtual int GetCacheMiss ()
 
virtual vtkIdType GetLastCellId ()
 
virtual void SetLastCellId (vtkIdType c)
 
virtual char * GetVectorsSelection ()
 
virtual int GetVectorsType ()
 
virtual void SetNormalizeVector (bool)
 
virtual bool GetNormalizeVector ()
 
virtual void CopyParameters (vtkAbstractInterpolatedVelocityField *from)
 
int GetLastWeights (double *w)
 
int GetLastLocalCoordinates (double pcoords[3])
 

Static Public Member Functions

static int IsTypeOf (const char *type)
 
static
vtkAbstractInterpolatedVelocityField
SafeDownCast (vtkObjectBase *o)
 

Protected Member Functions

virtual vtkObjectBase * NewInstanceInternal () const
 
 vtkAbstractInterpolatedVelocityField ()
 
 ~vtkAbstractInterpolatedVelocityField ()
 
virtual int FunctionValues (vtkDataSet *ds, double *x, double *f)
 
virtual void SetVectorsSelection (const char *)
 
void FastCompute (vtkDataArray *vectors, double f[3])
 
bool InterpolatePoint (vtkPointData *outPD, vtkIdType outIndex)
 
vtkGenericCell * GetLastCell ()
 

Protected Attributes

int CacheHit
 
int CacheMiss
 
int WeightsSize
 
bool Caching
 
bool NormalizeVector
 
int VectorsType
 
char * VectorsSelection
 
double * Weights
 
double LastPCoords [3]
 
vtkIdType LastCellId
 
vtkDataSet * LastDataSet
 
vtkGenericCell * Cell
 
vtkGenericCell * GenCell
 

Static Protected Attributes

static const double TOLERANCE_SCALE
 

Friends

class vtkTemporalInterpolatedVelocityField
 

Detailed Description

An abstract class for obtaining the interpolated velocity values at a point.

vtkAbstractInterpolatedVelocityField acts as a continuous velocity field by performing cell interpolation on the underlying vtkDataSet. This is an abstract sub-class of vtkFunctionSet, NumberOfIndependentVariables = 4 (x,y,z,t) and NumberOfFunctions = 3 (u,v,w). With a brute-force scheme, every time an evaluation is performed, the target cell containing point (x,y,z) needs to be found by calling FindCell(), via either vtkDataSet or vtkAbstractCelllocator's sub-classes (vtkCellLocator & vtkModifiedBSPTree). As it incurs a large cost, one (for vtkCellLocatorInterpolatedVelocityField via vtkAbstractCellLocator) or two (for vtkInterpolatedVelocityField via vtkDataSet that involves vtkPointLocator in addressing vtkPointSet) levels of cell caching may be exploited to increase the performance.

For vtkInterpolatedVelocityField, level #0 begins with intra-cell caching. Specifically if the previous cell is valid and the next point is still in it ( i.e., vtkCell::EvaluatePosition() returns 1, coupled with newly created parametric coordinates & weights ), the function values can be interpolated and only vtkCell::EvaluatePosition() is invoked. If this fails, then level #1 follows by inter-cell search for the target cell that contains the next point. By an inter-cell search, the previous cell provides an important clue or serves as an immediate neighbor to aid in locating the target cell via vtkPointSet:: FindCell(). If this still fails, a global cell location / search is invoked via vtkPointSet::FindCell(). Here regardless of either inter-cell or global search, vtkPointLocator is in fact employed (for datasets of type vtkPointSet only, note vtkImageData and vtkRectilinearGrid are able to provide rapid and robust cell location due to the simple mesh topology) as a crucial tool underlying the cell locator. However, the use of vtkPointLocator makes vtkInterpolatedVelocityField non-robust in cell location for vtkPointSet.

For vtkCellLocatorInterpolatedVelocityField, the only caching (level #0) works by intra-cell trial. In case of failure, a global search for the target cell is invoked via vtkAbstractCellLocator::FindCell() and the actual work is done by either vtkCellLocator or vtkModifiedBSPTree (for datasets of type vtkPointSet only, while vtkImageData and vtkRectilinearGrid themselves are able to provide fast robust cell location). Without the involvement of vtkPointLocator, robust cell location is achieved for vtkPointSet.

Warning
vtkAbstractInterpolatedVelocityField is not thread safe. A new instance should be created by each thread.
See Also
vtkInterpolatedVelocityField vtkCellLocatorInterpolatedVelocityField vtkGenericInterpolatedVelocityField vtkCachingInterpolatedVelocityField vtkTemporalInterpolatedVelocityField vtkFunctionSet vtkStreamer vtkStreamTracer

Definition at line 84 of file vtkAbstractInterpolatedVelocityField.h.

Member Typedef Documentation

Definition at line 87 of file vtkAbstractInterpolatedVelocityField.h.

Constructor & Destructor Documentation

vtkAbstractInterpolatedVelocityField::vtkAbstractInterpolatedVelocityField ( )
protected
vtkAbstractInterpolatedVelocityField::~vtkAbstractInterpolatedVelocityField ( )
protected

Member Function Documentation

static int vtkAbstractInterpolatedVelocityField::IsTypeOf ( const char *  type)
static
virtual int vtkAbstractInterpolatedVelocityField::IsA ( const char *  type)
virtual
static vtkAbstractInterpolatedVelocityField* vtkAbstractInterpolatedVelocityField::SafeDownCast ( vtkObjectBase *  o)
static
virtual vtkObjectBase* vtkAbstractInterpolatedVelocityField::NewInstanceInternal ( ) const
protectedvirtual
vtkAbstractInterpolatedVelocityField* vtkAbstractInterpolatedVelocityField::NewInstance ( ) const
void vtkAbstractInterpolatedVelocityField::PrintSelf ( ostream &  os,
vtkIndent  indent 
)
virtual void vtkAbstractInterpolatedVelocityField::SetCaching ( bool  )
virtual

Set/Get the caching flag. If this flag is turned ON, there are two levels of caching for derived concrete class vtkInterpolatedVelocityField and one level of caching for derived concrete class vtkCellLocatorInterpolatedVelocityField. Otherwise a global cell location is always invoked for evaluating the function values at any point.

virtual bool vtkAbstractInterpolatedVelocityField::GetCaching ( )
virtual

Set/Get the caching flag. If this flag is turned ON, there are two levels of caching for derived concrete class vtkInterpolatedVelocityField and one level of caching for derived concrete class vtkCellLocatorInterpolatedVelocityField. Otherwise a global cell location is always invoked for evaluating the function values at any point.

virtual int vtkAbstractInterpolatedVelocityField::GetCacheHit ( )
virtual

Get the caching statistics. CacheHit refers to the number of level #0 cache hits while CacheMiss is the number of level #0 cache misses.

virtual int vtkAbstractInterpolatedVelocityField::GetCacheMiss ( )
virtual

Get the caching statistics. CacheHit refers to the number of level #0 cache hits while CacheMiss is the number of level #0 cache misses.

virtual vtkDataSet* vtkAbstractInterpolatedVelocityField::GetLastDataSet ( )
virtual
virtual vtkIdType vtkAbstractInterpolatedVelocityField::GetLastCellId ( )
virtual

Get/Set the id of the cell cached from last evaluation.

virtual void vtkAbstractInterpolatedVelocityField::SetLastCellId ( vtkIdType  c)
inlinevirtual

Get/Set the id of the cell cached from last evaluation.

Reimplemented in vtkCellLocatorInterpolatedVelocityField, vtkInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

Definition at line 113 of file vtkAbstractInterpolatedVelocityField.h.

virtual void vtkAbstractInterpolatedVelocityField::SetLastCellId ( vtkIdType  c,
int  dataindex 
)
pure virtual

Set the id of the most recently visited cell of a dataset.

Implemented in vtkCellLocatorInterpolatedVelocityField, vtkInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

virtual char* vtkAbstractInterpolatedVelocityField::GetVectorsSelection ( )
virtual

Get/Set the name of a spcified vector array. By default it is NULL, with the active vector array for use.

virtual int vtkAbstractInterpolatedVelocityField::GetVectorsType ( )
virtual

Get/Set the name of a spcified vector array. By default it is NULL, with the active vector array for use.

void vtkAbstractInterpolatedVelocityField::SelectVectors ( int  fieldAssociation,
const char *  fieldName 
)

the association type (see vtkDataObject::FieldAssociations) and the name of the velocity data field

virtual void vtkAbstractInterpolatedVelocityField::SetNormalizeVector ( bool  )
virtual

Set/Get the flag indicating vector post-normalization (following vector interpolation). Vector post-normalization is required to avoid the 'curve-overshooting' problem (caused by high velocity magnitude) that occurs when Cell-Length is used as the step size unit (particularly the Minimum step size unit). Furthermore, it is required by RK45 to achieve, as expected, high numerical accuracy (or high smoothness of flow lines) through adaptive step sizing. Note this operation is performed (when NormalizeVector TRUE) right after vector interpolation such that the differing amount of contribution of each node (of a cell) to the resulting direction of the interpolated vector, due to the possibly significantly-differing velocity magnitude values at the nodes (which is the case with large cells), can be reflected as is. Also note that this flag needs to be turned to FALSE after vtkInitialValueProblemSolver:: ComputeNextStep() as subsequent operations, e.g., vorticity computation, may need non-normalized vectors.

virtual bool vtkAbstractInterpolatedVelocityField::GetNormalizeVector ( )
virtual

Set/Get the flag indicating vector post-normalization (following vector interpolation). Vector post-normalization is required to avoid the 'curve-overshooting' problem (caused by high velocity magnitude) that occurs when Cell-Length is used as the step size unit (particularly the Minimum step size unit). Furthermore, it is required by RK45 to achieve, as expected, high numerical accuracy (or high smoothness of flow lines) through adaptive step sizing. Note this operation is performed (when NormalizeVector TRUE) right after vector interpolation such that the differing amount of contribution of each node (of a cell) to the resulting direction of the interpolated vector, due to the possibly significantly-differing velocity magnitude values at the nodes (which is the case with large cells), can be reflected as is. Also note that this flag needs to be turned to FALSE after vtkInitialValueProblemSolver:: ComputeNextStep() as subsequent operations, e.g., vorticity computation, may need non-normalized vectors.

virtual void vtkAbstractInterpolatedVelocityField::CopyParameters ( vtkAbstractInterpolatedVelocityField from)
inlinevirtual

Import parameters. Sub-classes can add more after chaining.

Reimplemented in vtkCellLocatorInterpolatedVelocityField.

Definition at line 154 of file vtkAbstractInterpolatedVelocityField.h.

virtual int vtkAbstractInterpolatedVelocityField::FunctionValues ( double *  x,
double *  f 
)
pure virtual

Evaluate the velocity field f at point (x, y, z).

Implemented in vtkCellLocatorInterpolatedVelocityField, vtkInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

void vtkAbstractInterpolatedVelocityField::ClearLastCellId ( )
inline

Set the last cell id to -1 to incur a global cell search for the next point.

Definition at line 164 of file vtkAbstractInterpolatedVelocityField.h.

int vtkAbstractInterpolatedVelocityField::GetLastWeights ( double *  w)

Get the interpolation weights cached from last evaluation. Return 1 if the cached cell is valid and 0 otherwise.

int vtkAbstractInterpolatedVelocityField::GetLastLocalCoordinates ( double  pcoords[3])

Get the interpolation weights cached from last evaluation. Return 1 if the cached cell is valid and 0 otherwise.

virtual void vtkAbstractInterpolatedVelocityField::SetVectorsSelection ( const char *  )
protectedvirtual

Set the name of a specific vector to be interpolated.

virtual int vtkAbstractInterpolatedVelocityField::FunctionValues ( vtkDataSet *  ds,
double *  x,
double *  f 
)
protectedvirtual

Evaluate the velocity field f at point (x, y, z) in a specified dataset by invoking vtkDataSet::FindCell() to locate the next cell if the given point is outside the current cell. To address vtkPointSet, vtkPointLocator is involved via vtkPointSet::FindCell() in vtkInterpolatedVelocityField for cell location. In vtkCellLocatorInterpolatedVelocityField, this function is invoked just to handle vtkImageData and vtkRectilinearGrid that are not assigned with any vtkAbstractCellLocatot-type cell locator.

Reimplemented in vtkCellLocatorInterpolatedVelocityField, vtkInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

void vtkAbstractInterpolatedVelocityField::FastCompute ( vtkDataArray *  vectors,
double  f[3] 
)
protected

If all weights have been computed (parametric coords etc all valid), a scalar/vector can be quickly interpolated using the known weights and the cached generic cell. This function is primarily reserved for use by vtkTemporalInterpolatedVelocityField

bool vtkAbstractInterpolatedVelocityField::InterpolatePoint ( vtkPointData *  outPD,
vtkIdType  outIndex 
)
protected

If all weights have been computed (parametric coords etc all valid), a scalar/vector can be quickly interpolated using the known weights and the cached generic cell. This function is primarily reserved for use by vtkTemporalInterpolatedVelocityField

vtkGenericCell* vtkAbstractInterpolatedVelocityField::GetLastCell ( )
inlineprotected

If all weights have been computed (parametric coords etc all valid), a scalar/vector can be quickly interpolated using the known weights and the cached generic cell. This function is primarily reserved for use by vtkTemporalInterpolatedVelocityField

Definition at line 218 of file vtkAbstractInterpolatedVelocityField.h.

Friends And Related Function Documentation

Definition at line 210 of file vtkAbstractInterpolatedVelocityField.h.

Member Data Documentation

const double vtkAbstractInterpolatedVelocityField::TOLERANCE_SCALE
staticprotected

Definition at line 177 of file vtkAbstractInterpolatedVelocityField.h.

int vtkAbstractInterpolatedVelocityField::CacheHit
protected

Definition at line 179 of file vtkAbstractInterpolatedVelocityField.h.

int vtkAbstractInterpolatedVelocityField::CacheMiss
protected

Definition at line 180 of file vtkAbstractInterpolatedVelocityField.h.

int vtkAbstractInterpolatedVelocityField::WeightsSize
protected

Definition at line 181 of file vtkAbstractInterpolatedVelocityField.h.

bool vtkAbstractInterpolatedVelocityField::Caching
protected

Definition at line 182 of file vtkAbstractInterpolatedVelocityField.h.

bool vtkAbstractInterpolatedVelocityField::NormalizeVector
protected

Definition at line 183 of file vtkAbstractInterpolatedVelocityField.h.

int vtkAbstractInterpolatedVelocityField::VectorsType
protected

Definition at line 184 of file vtkAbstractInterpolatedVelocityField.h.

char* vtkAbstractInterpolatedVelocityField::VectorsSelection
protected

Definition at line 185 of file vtkAbstractInterpolatedVelocityField.h.

double* vtkAbstractInterpolatedVelocityField::Weights
protected

Definition at line 186 of file vtkAbstractInterpolatedVelocityField.h.

double vtkAbstractInterpolatedVelocityField::LastPCoords[3]
protected

Definition at line 187 of file vtkAbstractInterpolatedVelocityField.h.

vtkIdType vtkAbstractInterpolatedVelocityField::LastCellId
protected

Definition at line 188 of file vtkAbstractInterpolatedVelocityField.h.

vtkDataSet* vtkAbstractInterpolatedVelocityField::LastDataSet
protected

Definition at line 189 of file vtkAbstractInterpolatedVelocityField.h.

vtkGenericCell* vtkAbstractInterpolatedVelocityField::Cell
protected

Definition at line 190 of file vtkAbstractInterpolatedVelocityField.h.

vtkGenericCell* vtkAbstractInterpolatedVelocityField::GenCell
protected

Definition at line 191 of file vtkAbstractInterpolatedVelocityField.h.


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