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vtkGeneralizedKernel Class Referenceabstract

flexible, general interpolation kernels More...

#include <vtkGeneralizedKernel.h>

Inheritance diagram for vtkGeneralizedKernel:
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Collaboration diagram for vtkGeneralizedKernel:
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Public Types

enum  KernelStyle { RADIUS = 0, N_CLOSEST = 1 }
 Enum used to select the interpolation basis form. More...
 
typedef vtkInterpolationKernel Superclass
 Standard methods for type and printing. More...
 

Public Member Functions

virtual vtkTypeBool IsA (const char *type)
 Return 1 if this class is the same type of (or a subclass of) the named class. More...
 
vtkGeneralizedKernelNewInstance () const
 
void PrintSelf (ostream &os, vtkIndent indent) override
 Methods invoked by print to print information about the object including superclasses. More...
 
vtkIdType ComputeBasis (double x[3], vtkIdList *pIds, vtkIdType ptId=0) override
 Based on the kernel style, invoke the appropriate locator method to obtain the points making up the basis. More...
 
virtual vtkIdType ComputeWeights (double x[3], vtkIdList *pIds, vtkDoubleArray *prob, vtkDoubleArray *weights)=0
 Given a point x, a list of basis points pIds, and a probability weighting function prob, compute interpolation weights associated with these basis points. More...
 
vtkIdType ComputeWeights (double x[3], vtkIdList *pIds, vtkDoubleArray *weights) override
 Given a point x, and a list of basis points pIds, compute interpolation weights associated with these basis points. More...
 
virtual void SetKernelFootprint (int)
 Specify the interpolation basis style. More...
 
virtual int GetKernelFootprint ()
 
void SetKernelFootprintToRadius ()
 
void SetKernelFootprintToNClosest ()
 
virtual void SetRadius (double)
 If the interpolation basis style is Radius, then this method specifies the radius within which the basis points must lie. More...
 
virtual double GetRadius ()
 
virtual void SetNumberOfPoints (int)
 If the interpolation basis style is NClosest, then this method specifies the number of the closest points used to form the interpolation basis. More...
 
virtual int GetNumberOfPoints ()
 
virtual void SetNormalizeWeights (bool)
 Indicate whether the interpolation weights should be normalized after they are computed. More...
 
virtual bool GetNormalizeWeights ()
 
virtual void NormalizeWeightsOn ()
 
virtual void NormalizeWeightsOff ()
 
- Public Member Functions inherited from vtkInterpolationKernel
 vtkAbstractTypeMacro (vtkInterpolationKernel, vtkObject)
 Standard method for type and printing. More...
 
void PrintSelf (ostream &os, vtkIndent indent) override
 Methods invoked by print to print information about the object including superclasses. More...
 
virtual void Initialize (vtkAbstractPointLocator *loc, vtkDataSet *ds, vtkPointData *pd)
 Initialize the kernel. More...
 
virtual void SetRequiresInitialization (bool)
 Indicate whether the kernel needs initialization. More...
 
virtual bool GetRequiresInitialization ()
 
virtual void RequiresInitializationOn ()
 
virtual void RequiresInitializationOff ()
 
- Public Member Functions inherited from vtkObject
 vtkBaseTypeMacro (vtkObject, vtkObjectBase)
 
virtual void DebugOn ()
 Turn debugging output on. More...
 
virtual void DebugOff ()
 Turn debugging output off. More...
 
bool GetDebug ()
 Get the value of the debug flag. More...
 
void SetDebug (bool debugFlag)
 Set the value of the debug flag. More...
 
virtual void Modified ()
 Update the modification time for this object. More...
 
virtual vtkMTimeType GetMTime ()
 Return this object's modified time. More...
 
unsigned long AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
unsigned long AddObserver (const char *event, vtkCommand *, float priority=0.0f)
 
vtkCommandGetCommand (unsigned long tag)
 
void RemoveObserver (vtkCommand *)
 
void RemoveObservers (unsigned long event, vtkCommand *)
 
void RemoveObservers (const char *event, vtkCommand *)
 
vtkTypeBool HasObserver (unsigned long event, vtkCommand *)
 
vtkTypeBool HasObserver (const char *event, vtkCommand *)
 
void RemoveObserver (unsigned long tag)
 
void RemoveObservers (unsigned long event)
 
void RemoveObservers (const char *event)
 
void RemoveAllObservers ()
 
vtkTypeBool HasObserver (unsigned long event)
 
vtkTypeBool HasObserver (const char *event)
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)
 Overloads to AddObserver that allow developers to add class member functions as callbacks for events. More...
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, bool(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
 Allow user to set the AbortFlagOn() with the return value of the callback method. More...
 
int InvokeEvent (unsigned long event, void *callData)
 This method invokes an event and return whether the event was aborted or not. More...
 
int InvokeEvent (const char *event, void *callData)
 
int InvokeEvent (unsigned long event)
 
int InvokeEvent (const char *event)
 
- Public Member Functions inherited from vtkObjectBase
const char * GetClassName () const
 Return the class name as a string. More...
 
virtual void Delete ()
 Delete a VTK object. More...
 
virtual void FastDelete ()
 Delete a reference to this object. More...
 
void InitializeObjectBase ()
 
void Print (ostream &os)
 Print an object to an ostream. More...
 
virtual void PrintHeader (ostream &os, vtkIndent indent)
 
virtual void PrintTrailer (ostream &os, vtkIndent indent)
 
virtual void Register (vtkObjectBase *o)
 Increase the reference count (mark as used by another object). More...
 
virtual void UnRegister (vtkObjectBase *o)
 Decrease the reference count (release by another object). More...
 
int GetReferenceCount ()
 Return the current reference count of this object. More...
 
void SetReferenceCount (int)
 Sets the reference count. More...
 
void PrintRevisions (ostream &)
 Legacy. More...
 

Static Public Member Functions

static vtkTypeBool IsTypeOf (const char *type)
 
static vtkGeneralizedKernelSafeDownCast (vtkObjectBase *o)
 
- Static Public Member Functions inherited from vtkObject
static vtkObjectNew ()
 Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...
 
static void BreakOnError ()
 This method is called when vtkErrorMacro executes. More...
 
static void SetGlobalWarningDisplay (int val)
 This is a global flag that controls whether any debug, warning or error messages are displayed. More...
 
static void GlobalWarningDisplayOn ()
 
static void GlobalWarningDisplayOff ()
 
static int GetGlobalWarningDisplay ()
 
- Static Public Member Functions inherited from vtkObjectBase
static vtkTypeBool IsTypeOf (const char *name)
 Return 1 if this class type is the same type of (or a subclass of) the named class. More...
 
static vtkObjectBaseNew ()
 Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...
 

Protected Member Functions

virtual vtkObjectBaseNewInstanceInternal () const
 
 vtkGeneralizedKernel ()
 
 ~vtkGeneralizedKernel () override
 
- Protected Member Functions inherited from vtkInterpolationKernel
 vtkInterpolationKernel ()
 
 ~vtkInterpolationKernel () override
 
virtual void FreeStructures ()
 
- Protected Member Functions inherited from vtkObject
 vtkObject ()
 
 ~vtkObject () override
 
void RegisterInternal (vtkObjectBase *, vtkTypeBool check) override
 
void UnRegisterInternal (vtkObjectBase *, vtkTypeBool check) override
 
void InternalGrabFocus (vtkCommand *mouseEvents, vtkCommand *keypressEvents=nullptr)
 These methods allow a command to exclusively grab all events. More...
 
void InternalReleaseFocus ()
 
- Protected Member Functions inherited from vtkObjectBase
 vtkObjectBase ()
 
virtual ~vtkObjectBase ()
 
virtual void CollectRevisions (ostream &)
 
virtual void ReportReferences (vtkGarbageCollector *)
 
 vtkObjectBase (const vtkObjectBase &)
 
void operator= (const vtkObjectBase &)
 

Protected Attributes

int KernelFootprint
 
double Radius
 
int NumberOfPoints
 
bool NormalizeWeights
 
- Protected Attributes inherited from vtkInterpolationKernel
bool RequiresInitialization
 
vtkAbstractPointLocatorLocator
 
vtkDataSetDataSet
 
vtkPointDataPointData
 
- Protected Attributes inherited from vtkObject
bool Debug
 
vtkTimeStamp MTime
 
vtkSubjectHelper * SubjectHelper
 
- Protected Attributes inherited from vtkObjectBase
std::atomic< int32_t > ReferenceCount
 
vtkWeakPointerBase ** WeakPointers
 

Detailed Description

flexible, general interpolation kernels

vtkGeneralizedKernel is an abstract class that defines an API for concrete general-purpose, kernel subclasses. vtkGeneralizedKernels has important properties that make them useful in a variety of interpolation applications:

1. The weights are normalized.
2. The footprint of the basis is configurable.
3. Probabilistic weighting functions can be used to favor certain weights.

The following paragraphs describe each of these properties in more detail.

Normalized weightings simple mean Sum(w_i) = 1. This ensures that the interpolation process is well behaved.

The interpolation footprint is the set of points that are used to perform the interpolation process. For example, it is possible to choose between a radius-based kernel selection, and one based on the N nearest neighbors. Note that the performance and mathematical properties of kernels may vary greatly depending on which kernel style is selected. For example, if a radius-based kernel footprint is used, and the radius is too big, the algorithm can perform in n^3 fashion.

Finally, in advanced usage, probability functions can be applied to the interpolation weights (prior to normalization). These probability functions are confidence estimates that the data at a particular point is accurate. A typical application is when laser scans are used to acquire point measurements, which return normals that indicate glancing returns versus direct, near orthogonal hits. Another use is when point clouds are combined, where some clouds are acquired with more accurate, detailed devices versus a broad, potentially coarser acquisition process.

Warning
Some kernels, like the Voronoi kernel, cannot be subclasses of this class because their definition inherently defines the basis style. For example, the Voronoi kernel is simply the single closest point. SPH kernels are similar, because they implicitly depend on a particle distribution consistent with simulation constraints such as conservation of mass, etc.
See also
vtkPointInterpolator vtkPointInterpolator2D vtkGaussianKernel vtkSPHKernel vtkShepardKernel vtkLinearKernel vtkVoronoiKernel

Definition at line 69 of file vtkGeneralizedKernel.h.

Member Typedef Documentation

◆ Superclass

Standard methods for type and printing.

Definition at line 76 of file vtkGeneralizedKernel.h.

Member Enumeration Documentation

◆ KernelStyle

Enum used to select the interpolation basis form.

By default, a Radius form is used (i.e., the basis is defined from all points within a specified radius). However, it is also possible to select the N closest points (NClosest).

Enumerator
RADIUS 
N_CLOSEST 

Definition at line 129 of file vtkGeneralizedKernel.h.

Constructor & Destructor Documentation

◆ vtkGeneralizedKernel()

vtkGeneralizedKernel::vtkGeneralizedKernel ( )
protected

◆ ~vtkGeneralizedKernel()

vtkGeneralizedKernel::~vtkGeneralizedKernel ( )
overrideprotected

Member Function Documentation

◆ IsTypeOf()

static vtkTypeBool vtkGeneralizedKernel::IsTypeOf ( const char *  type)
static

◆ IsA()

virtual vtkTypeBool vtkGeneralizedKernel::IsA ( const char *  name)
virtual

Return 1 if this class is the same type of (or a subclass of) the named class.

Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.

Reimplemented from vtkObjectBase.

Reimplemented in vtkEllipsoidalGaussianKernel, vtkGaussianKernel, vtkProbabilisticVoronoiKernel, vtkShepardKernel, and vtkLinearKernel.

◆ SafeDownCast()

static vtkGeneralizedKernel* vtkGeneralizedKernel::SafeDownCast ( vtkObjectBase o)
static

◆ NewInstanceInternal()

virtual vtkObjectBase* vtkGeneralizedKernel::NewInstanceInternal ( ) const
protectedvirtual

◆ NewInstance()

vtkGeneralizedKernel* vtkGeneralizedKernel::NewInstance ( ) const

◆ PrintSelf()

void vtkGeneralizedKernel::PrintSelf ( ostream &  os,
vtkIndent  indent 
)
overridevirtual

Methods invoked by print to print information about the object including superclasses.

Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from vtkObject.

Reimplemented in vtkProbabilisticVoronoiKernel, vtkShepardKernel, and vtkLinearKernel.

◆ ComputeBasis()

vtkIdType vtkGeneralizedKernel::ComputeBasis ( double  x[3],
vtkIdList pIds,
vtkIdType  ptId = 0 
)
overridevirtual

Based on the kernel style, invoke the appropriate locator method to obtain the points making up the basis.

Given a point x (and optional associated point id), determine the points around x which form an interpolation basis. The user must provide the vtkIdList pIds, which will be dynamically resized as necessary. The method returns the number of points in the basis. Typically this method is called before ComputeWeights(). Note that ptId is optional in most cases, although in some kernels it is used to facilitate basis computation.

Implements vtkInterpolationKernel.

◆ ComputeWeights() [1/2]

virtual vtkIdType vtkGeneralizedKernel::ComputeWeights ( double  x[3],
vtkIdList pIds,
vtkDoubleArray prob,
vtkDoubleArray weights 
)
pure virtual

Given a point x, a list of basis points pIds, and a probability weighting function prob, compute interpolation weights associated with these basis points.

Note that basis points list pIds, the probability weighting prob, and the weights array are provided by the caller of the method, and may be dynamically resized as necessary. The method returns the number of weights (pIds may be resized in some cases). Typically this method is called after ComputeBasis(), although advanced users can invoke ComputeWeights() and provide the interpolation basis points pIds directly. The probably weighting prob are numbers 0<=prob<=1 which are multiplied against the interpolation weights before normalization. They are estimates of local confidence of weights. The prob may be nullptr in which all probabilities are considered =1.

Implemented in vtkEllipsoidalGaussianKernel, vtkGaussianKernel, vtkProbabilisticVoronoiKernel, vtkShepardKernel, and vtkLinearKernel.

◆ ComputeWeights() [2/2]

vtkIdType vtkGeneralizedKernel::ComputeWeights ( double  x[3],
vtkIdList pIds,
vtkDoubleArray weights 
)
inlineoverridevirtual

Given a point x, and a list of basis points pIds, compute interpolation weights associated with these basis points.

Note that both the nearby basis points list pIds and the weights array are provided by the caller of the method, and may be dynamically resized as necessary. Typically this method is called after ComputeBasis(), although advanced users can invoke ComputeWeights() and provide the interpolation basis points pIds directly.

Implements vtkInterpolationKernel.

Definition at line 118 of file vtkGeneralizedKernel.h.

◆ SetKernelFootprint()

virtual void vtkGeneralizedKernel::SetKernelFootprint ( int  )
virtual

Specify the interpolation basis style.

By default, a Radius style is used (i.e., the basis is defined from all points within a specified radius). However, it is also possible to select the N closest points (NClosest). Note that in most formulations the Radius style is assumed as it provides better mathematical properties. However, for convenience some bases are easier to use when the N closest points are taken.

◆ GetKernelFootprint()

virtual int vtkGeneralizedKernel::GetKernelFootprint ( )
virtual

◆ SetKernelFootprintToRadius()

void vtkGeneralizedKernel::SetKernelFootprintToRadius ( )
inline

Definition at line 146 of file vtkGeneralizedKernel.h.

◆ SetKernelFootprintToNClosest()

void vtkGeneralizedKernel::SetKernelFootprintToNClosest ( )
inline

Definition at line 147 of file vtkGeneralizedKernel.h.

◆ SetRadius()

virtual void vtkGeneralizedKernel::SetRadius ( double  )
virtual

If the interpolation basis style is Radius, then this method specifies the radius within which the basis points must lie.

◆ GetRadius()

virtual double vtkGeneralizedKernel::GetRadius ( )
virtual

◆ SetNumberOfPoints()

virtual void vtkGeneralizedKernel::SetNumberOfPoints ( int  )
virtual

If the interpolation basis style is NClosest, then this method specifies the number of the closest points used to form the interpolation basis.

◆ GetNumberOfPoints()

virtual int vtkGeneralizedKernel::GetNumberOfPoints ( )
virtual

◆ SetNormalizeWeights()

virtual void vtkGeneralizedKernel::SetNormalizeWeights ( bool  )
virtual

Indicate whether the interpolation weights should be normalized after they are computed.

Generally this is left on as it results in more reasonable behavior.

◆ GetNormalizeWeights()

virtual bool vtkGeneralizedKernel::GetNormalizeWeights ( )
virtual

◆ NormalizeWeightsOn()

virtual void vtkGeneralizedKernel::NormalizeWeightsOn ( )
virtual

◆ NormalizeWeightsOff()

virtual void vtkGeneralizedKernel::NormalizeWeightsOff ( )
virtual

Member Data Documentation

◆ KernelFootprint

int vtkGeneralizedKernel::KernelFootprint
protected

Definition at line 183 of file vtkGeneralizedKernel.h.

◆ Radius

double vtkGeneralizedKernel::Radius
protected

Definition at line 184 of file vtkGeneralizedKernel.h.

◆ NumberOfPoints

int vtkGeneralizedKernel::NumberOfPoints
protected

Definition at line 185 of file vtkGeneralizedKernel.h.

◆ NormalizeWeights

bool vtkGeneralizedKernel::NormalizeWeights
protected

Definition at line 186 of file vtkGeneralizedKernel.h.


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