QwtSpline Class Reference

Base class for all splines. More...

#include <qwt_spline.h>

Inheritance diagram for QwtSpline:

Classes
class	PrivateData

Public Types
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
	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 QPolygonF	polygon (const QPolygonF &, double tolerance) const
	Get polygon approximation with tolerance.
virtual QPainterPath	painterPath (const QPolygonF &) const =0
	Get painter path from polygon (pure virtual)
virtual uint	locality () const
	Get locality (number of points used for calculation)

Detailed Description

Base class for all splines.

Member Enumeration Documentation

BoundaryCondition

enum QwtSpline::BoundaryCondition

Boundary condition.

Enumerator
Clamped1	The first derivative at the end point is given See also boundaryValue()
Clamped2	The second derivative at the end point is given See also boundaryValue() Note a condition having a second derivative of 0 is also called "natural".
Clamped3	The third derivative at the end point is given See also boundaryValue() Note a condition having a third derivative of 0 is also called "parabolic runout".
LinearRunout	The first derivate at the endpoint is related to the first derivative at its neighbour by the boundary value. F,e when the boundary value at the end is 1.0 then the slope at the last 2 points is the same. See also boundaryValue().

BoundaryPosition

enum QwtSpline::BoundaryPosition

position of a boundary condition

Enumerator
AtBeginning	the condition is at the beginning of the polynomial
AtEnd	the condition is at the end of the polynomial

BoundaryType

enum QwtSpline::BoundaryType

Boundary type specifying the spline at its endpoints.

Enumerator
ConditionalBoundaries	The polynomials at the start/endpoint depend on specific conditions See also QwtSpline::BoundaryCondition
PeriodicPolygon	The polynomials at the start/endpoint are found by using imaginary additional points. Additional points at the end are found by translating points from the beginning or v.v.
ClosedPolygon	ClosedPolygon is similar to PeriodicPolygon beside, that the interpolation includes the connection between the last and the first control point. Note Only works for parametrizations, where the parameter increment for the the final closing line is positive. This excludes QwtSplineParametrization::ParameterX and QwtSplineParametrization::ParameterY

Constructor & Destructor Documentation

QwtSpline()

QwtSpline::QwtSpline

(

)

Constructor.

~QwtSpline()

QwtSpline::~QwtSpline ( )

virtual

Destructor.

Destructor

.

Member Function Documentation

boundaryCondition()

int QwtSpline::boundaryCondition

(

BoundaryPosition

position

)

const

Get boundary condition.

boundaryType()

QwtSpline::BoundaryType QwtSpline::boundaryType

(

)

const

Get boundary type.

boundaryValue()

double QwtSpline::boundaryValue

(

BoundaryPosition

position

)

const

Get boundary value.

locality()

uint QwtSpline::locality ( ) const

virtual

Get locality (number of points used for calculation)

Get the locality of the spline interpolation.

Reimplemented in QwtSplineBasis, QwtSplineCubic, QwtSplineLocal, and QwtSplinePleasing.

painterPath()

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

pure virtual

Get painter path from polygon (pure virtual)

Approximates a polygon piecewise with cubic Bezier curves and returns them as QPainterPath.

Parameters

points

Control points

Returns

Painter path, that can be rendered by QPainter

See also

polygon(), QwtBezier

Implemented in QwtSplineInterpolating, QwtSplineC1, QwtSplineC2, QwtSplineBasis, QwtSplineCubic, QwtSplineLocal, and QwtSplinePleasing.

parametrization()

const QwtSplineParametrization * QwtSpline::parametrization

(

)

const

Get parametrization.

polygon()

QPolygonF QwtSpline::polygon ( const QPolygonF &  points, double  tolerance  ) const

virtual

Get polygon approximation with tolerance.

Interpolate a curve by a polygon.

Reimplemented in QwtSplineInterpolating.

setBoundaryCondition()

void QwtSpline::setBoundaryCondition	(	BoundaryPosition	position,
		int	condition
	)

Set boundary condition.

setBoundaryConditions()

void QwtSpline::setBoundaryConditions	(	int	condition,
		double	valueBegin = 0.0,
		double	valueEnd = 0.0
	)

Set boundary conditions for both ends.

setBoundaryType()

void QwtSpline::setBoundaryType

(

BoundaryType

boundaryType

)

Set boundary type.

setBoundaryValue()

void QwtSpline::setBoundaryValue	(	BoundaryPosition	position,
		double	value
	)

Set boundary value.

setParametrization() [1/2]

void QwtSpline::setParametrization

(

int

type

)

Set parametrization by type.

setParametrization() [2/2]

void QwtSpline::setParametrization

(

QwtSplineParametrization *

parametrization

)

Set parametrization object.

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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