QwtSplineC2 Class Reference

Base class for spline interpolations with C2 (second order parametric) continuity. More...

#include <qwt_spline.h>

Inheritance diagram for QwtSplineC2:

Public Types
enum	BoundaryConditionC2 { CubicRunout = LinearRunout + 1 , NotAKnot }
	Boundary condition that requires C2 continuity. More...
Public Types inherited from QwtSpline
enum	BoundaryType { ConditionalBoundaries , PeriodicPolygon , ClosedPolygon }
	Boundary type specifying the spline at its endpoints. More...
enum	BoundaryPosition { AtBeginning , AtEnd }
	position of a boundary condition More...
enum	BoundaryCondition { Clamped1 , Clamped2 , Clamped3 , LinearRunout }
	Boundary condition. More...

Public Member Functions
	QwtSplineC2 ()
	Constructor.
virtual	~QwtSplineC2 ()
	Destructor .
virtual QPainterPath	painterPath (const QPolygonF &) const override
	Interpolate a curve with Bezier curves.
virtual QVector< QLineF >	bezierControlLines (const QPolygonF &) const override
	Interpolate a curve with Bezier curves.
virtual QPolygonF	equidistantPolygon (const QPolygonF &, double distance, bool withNodes) const override
	Find an interpolated polygon with "equidistant" points.
virtual QVector< QwtSplinePolynomial >	polynomials (const QPolygonF &) const override
	Calculate the interpolating polynomials for a non-parametric spline.
virtual QVector< double >	slopes (const QPolygonF &) const override
	Find the first derivative at the control points.
virtual QVector< double >	curvatures (const QPolygonF &) const =0
	Find the second derivative at the control points.
Public Member Functions inherited from QwtSplineC1
	QwtSplineC1 ()
	Constructor.
virtual	~QwtSplineC1 ()
	Destructor .
virtual double	slopeAtBeginning (const QPolygonF &, double slopeNext) const
	Calculate the slope at the beginning of the spline.
virtual double	slopeAtEnd (const QPolygonF &, double slopeBefore) const
	Calculate the slope at the end of the spline.
Public Member Functions inherited from QwtSplineG1
	QwtSplineG1 ()
	Constructor .
virtual	~QwtSplineG1 ()
	Destructor .
Public Member Functions inherited from QwtSplineInterpolating
	QwtSplineInterpolating ()
	Constructor .
virtual	~QwtSplineInterpolating ()
	Destructor .
virtual QPolygonF	polygon (const QPolygonF &, double tolerance) const override
	Interpolate a curve by a polygon.
Public Member Functions inherited from QwtSpline
	QwtSpline ()
	Constructor.
virtual	~QwtSpline ()
	Destructor.
void	setParametrization (int type)
	Set parametrization by type.
void	setParametrization (QwtSplineParametrization *)
	Set parametrization object.
const QwtSplineParametrization *	parametrization () const
	Get parametrization.
void	setBoundaryType (BoundaryType)
	Set boundary type.
BoundaryType	boundaryType () const
	Get boundary type.
void	setBoundaryValue (BoundaryPosition, double value)
	Set boundary value.
double	boundaryValue (BoundaryPosition) const
	Get boundary value.
void	setBoundaryCondition (BoundaryPosition, int condition)
	Set boundary condition.
int	boundaryCondition (BoundaryPosition) const
	Get boundary condition.
void	setBoundaryConditions (int condition, double valueBegin=0.0, double valueEnd=0.0)
	Set boundary conditions for both ends.
virtual uint	locality () const
	Get locality (number of points used for calculation)

Detailed Description

Base class for spline interpolations with C2 (second order parametric) continuity.

Member Enumeration Documentation

BoundaryConditionC2

enum QwtSplineC2::BoundaryConditionC2

Boundary condition that requires C2 continuity.

See also

QwtSpline::boundaryCondition, QwtSpline::BoundaryCondition

Enumerator
CubicRunout	The second derivate at the endpoint is related to the second derivatives at the 2 neighbours: cv[0] := 2.0 * cv[1] - cv[2]. Note boundaryValue() is ignored
NotAKnot	The 3rd derivate at the endpoint matches the 3rd derivate at its neighbours. Or in other words: the first/last curve segment extents the polynomial of its neighboured polynomial Note boundaryValue() is ignored

Constructor & Destructor Documentation

QwtSplineC2()

QwtSplineC2::QwtSplineC2

(

)

Constructor.

~QwtSplineC2()

QwtSplineC2::~QwtSplineC2 ( )

virtual

Destructor .

Member Function Documentation

bezierControlLines()

QVector< QLineF > QwtSplineC2::bezierControlLines ( const QPolygonF &  points ) const

overridevirtual

Interpolate a curve with Bezier curves.

Reimplemented from QwtSplineC1.

Reimplemented in QwtSplineCubic.

curvatures()

QVector< double > QwtSplineC2::curvatures ( const QPolygonF &  points ) const

pure virtual

Find the second derivative at the control points.

Parameters

points

Control nodes of the spline

Returns

Vector with the values of the 2nd derivate at the control points

See also

slopes()

Note

The x coordinates need to be increasing or decreasing

Implemented in QwtSplineCubic.

equidistantPolygon()

QPolygonF QwtSplineC2::equidistantPolygon ( const QPolygonF &  points, double  distance, bool  withNodes  ) const

overridevirtual

Find an interpolated polygon with "equidistant" points.

Reimplemented from QwtSplineC1.

painterPath()

QPainterPath QwtSplineC2::painterPath ( const QPolygonF &  points ) const

overridevirtual

Interpolate a curve with Bezier curves.

Reimplemented from QwtSplineC1.

Reimplemented in QwtSplineCubic.

polynomials()

QVector< QwtSplinePolynomial > QwtSplineC2::polynomials ( const QPolygonF &  points ) const

overridevirtual

Calculate the interpolating polynomials for a non-parametric spline.

Reimplemented from QwtSplineC1.

Reimplemented in QwtSplineCubic.

slopes()

QVector< double > QwtSplineC2::slopes ( const QPolygonF &  points ) const

overridevirtual

Find the first derivative at the control points.

Implements QwtSplineC1.

Reimplemented in QwtSplineCubic.

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

• /home/runner/work/QWT/QWT/src/plot/qwt_spline.h
• /home/runner/work/QWT/QWT/src/plot/qwt_spline.cpp