qwtweedingcurvefitter(3) [debian man page]
QwtWeedingCurveFitter(3) Qwt User's Guide QwtWeedingCurveFitter(3) NAME
QwtWeedingCurveFitter - A curve fitter implementing Douglas and Peucker algorithm. SYNOPSIS
#include <qwt_curve_fitter.h> Inherits QwtCurveFitter. Public Member Functions QwtWeedingCurveFitter (double tolerance=1.0) virtual ~QwtWeedingCurveFitter () void setTolerance (double) double tolerance () const virtual QPolygonF fitCurve (const QPolygonF &) const Detailed Description A curve fitter implementing Douglas and Peucker algorithm. The purpose of the Douglas and Peucker algorithm is that given a 'curve' composed of line segments to find a curve not too dissimilar but that has fewer points. The algorithm defines 'too dissimilar' based on the maximum distance (tolerance) between the original curve and the smoothed curve. The smoothed curve consists of a subset of the points that defined the original curve. In opposite to QwtSplineCurveFitter the Douglas and Peucker algorithm reduces the number of points. By adjusting the tolerance parameter according to the axis scales QwtSplineCurveFitter can be used to implement different level of details to speed up painting of curves of many points. Constructor &; Destructor Documentation QwtWeedingCurveFitter::QwtWeedingCurveFitter (doubletolerance = 1.0) Constructor Parameters: tolerance Tolerance See also: setTolerance(), tolerance() QwtWeedingCurveFitter::~QwtWeedingCurveFitter () [virtual] Destructor. Member Function Documentation QPolygonF QwtWeedingCurveFitter::fitCurve (const QPolygonF &points) const [virtual] Parameters: points Series of data points Returns: Curve points Implements QwtCurveFitter. void QwtWeedingCurveFitter::setTolerance (doubletolerance) Assign the tolerance The tolerance is the maximum distance, that is accaptable between the original curve and the smoothed curve. Increasing the tolerance will reduce the number of the resulting points. Parameters: tolerance Tolerance See also: tolerance() double QwtWeedingCurveFitter::tolerance () const Returns: Tolerance See also: setTolerance() Author Generated automatically by Doxygen for Qwt User's Guide from the source code. Version 6.0.0 Fri Apr 15 2011 QwtWeedingCurveFitter(3)
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QwtPolygonFData(3) Qwt User's Guide QwtPolygonFData(3) NAME
QwtPolygonFData - Data class containing a single QwtArray<QwtDoublePoint> object. SYNOPSIS
#include <qwt_data.h> Inherits QwtData. Public Member Functions virtual QwtDoubleRect boundingRect () const virtual QwtData * copy () const const QPolygonF & data () const QwtPolygonFData & operator= (const QwtPolygonFData &) QwtPolygonFData (const QPolygonF &) virtual size_t size () const virtual double x (size_t i) const virtual double y (size_t i) const Detailed Description Data class containing a single QwtArray<QwtDoublePoint> object. Constructor &; Destructor Documentation QwtPolygonFData::QwtPolygonFData (const QPolygonF &polygon) Constructor Parameters: polygon Polygon data See also: QwtPlotCurve::setData() Member Function Documentation QwtDoubleRect QwtData::boundingRect () const [virtual, inherited] 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. QwtData * QwtPolygonFData::copy () const [virtual] Returns: Pointer to a copy (virtual copy constructor) Implements QwtData. const QPolygonF & QwtPolygonFData::data () const Returns: Point array QwtPolygonFData & QwtPolygonFData::operator= (const QwtPolygonFData &data) Assignment. size_t QwtPolygonFData::size () const [virtual] Returns: Size of the data set Implements QwtData. double QwtPolygonFData::x (size_ti) const [virtual] Return the x value of data point i Parameters: i Index Returns: x X value of data point i Implements QwtData. double QwtPolygonFData::y (size_ti) const [virtual] Return the y value of data point i Parameters: i Index Returns: y Y value of data point i Implements QwtData. Author Generated automatically by Doxygen for Qwt User's Guide from the source code. Version 5.2.2 Mon Aug 1 2011 QwtPolygonFData(3)