QwtSplineLocal Class Reference

A spline with C1 continuity. More...

#include <qwt_spline_local.h>

Inheritance diagram for QwtSplineLocal:

Public Types
enum	Type { Cardinal , ParabolicBlending , Akima , PChip }
	Spline interpolation type. 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
	QwtSplineLocal (Type type)
	Constructor with spline type.
virtual	~QwtSplineLocal ()
	Destructor.
Type	type () const
	Get spline type.
virtual uint	locality () const override
	Get locality (number of points used for calculation)
virtual QPainterPath	painterPath (const QPolygonF &) const override
	Get painter path from polygon.
virtual QVector< QLineF >	bezierControlLines (const QPolygonF &) const override
	Get Bezier control lines.
virtual QVector< QwtSplinePolynomial >	polynomials (const QPolygonF &) const override
	Get polynomials from polygon.
virtual QVector< double >	slopes (const QPolygonF &) const override
	Get slopes at control points.
Public Member Functions inherited from QwtSplineC1
	QwtSplineC1 ()
	Constructor.
virtual	~QwtSplineC1 ()
	Destructor .
virtual QPolygonF	equidistantPolygon (const QPolygonF &, double distance, bool withNodes) const override
	Find an interpolated polygon with "equidistant" points.
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.

Detailed Description

A spline with C1 continuity.

Member Enumeration Documentation

Type

enum QwtSplineLocal::Type

Spline interpolation type.

Enumerator
Cardinal	A cardinal spline The cardinal spline interpolation is a very cheap calculation with a locality of 1.
ParabolicBlending	Parabolic blending is a cheap calculation with a locality of 1. Sometimes it is also called Cubic Bessel interpolation.
Akima	The algorithm of H.Akima is a calculation with a locality of 2.
PChip	Piecewise Cubic Hermite Interpolating Polynomial (PCHIP) is an algorithm that is popular because of being offered by MATLAB. It preserves the shape of the data and respects monotonicity. It has a locality of 1.

Constructor & Destructor Documentation

QwtSplineLocal()

QwtSplineLocal::QwtSplineLocal ( Type  type )

explicit

Constructor with spline type.

Constructor.

~QwtSplineLocal()

QwtSplineLocal::~QwtSplineLocal ( )

virtual

Destructor.

Destructor

.

Member Function Documentation

bezierControlLines()

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

overridevirtual

Get Bezier control lines.

Interpolate a curve with Bezier curves.

Reimplemented from QwtSplineC1.

locality()

uint QwtSplineLocal::locality ( ) const

overridevirtual

Get locality (number of points used for calculation)

Get the locality of the spline interpolation.

Reimplemented from QwtSpline.

painterPath()

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

overridevirtual

Get painter path from polygon.

Interpolate a curve with Bezier curves.

Reimplemented from QwtSplineC1.

polynomials()

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

overridevirtual

Get polynomials from polygon.

Calculate the interpolating polynomials for a non parametric spline.

Reimplemented from QwtSplineC1.

slopes()

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

overridevirtual

Get slopes at control points.

Find the first derivative at the control points.

Implements QwtSplineC1.

type()

QwtSplineLocal::Type QwtSplineLocal::type

(

)

const

Get spline type.

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

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