QwtData - Man Page

Name

QwtData —

QwtData defines an interface to any type of curve data.

Synopsis

#include <qwt_data.h>

Inherited by QwtArrayData, QwtCPointerData, and QwtPolygonFData.

virtual QwtDoubleRect boundingRect () const
virtual QwtData * copy () const =0
QwtData ()
virtual size_t size () const =0
virtual double x (size_t i) const =0
virtual double y (size_t i) const =0
virtual ~QwtData ()

Protected Member Functions

QwtData & operator= (const QwtData &)

Detailed Description

QwtData defines an interface to any type of curve data.

Classes, derived from QwtData may:

store the data in almost any type of container
calculate the data on the fly instead of storing it

Constructor & Destructor Documentation

QwtData::QwtData ()

Constructor.

QwtData::~QwtData () [virtual]

Destructor.

Member Function Documentation

QwtDoubleRect QwtData::boundingRect () const [virtual] Returns the bounding rectangle of the data. If there is no bounding rect, like for empty data the rectangle is invalid: QwtDoubleRect::isValid() == false

Warning:: This is an slow implementation iterating over all points. It is intended to be overloaded by derived classes. In case of auto scaling boundingRect() is called for every replot, so it might be worth to implement a cache, or use x(0), x(size() - 1) for ordered data ...

Reimplemented in QwtArrayData, and QwtCPointerData.