conflicting packages
| QwtPlotCurve(3) | Qwt User's Guide | QwtPlotCurve(3) |
NAME¶
QwtPlotCurve - A plot item, that represents a series of points.SYNOPSIS¶
#include <qwt_plot_curve.h> Inherits QwtPlotSeriesItem< QPointF >.Public Types¶
enum CurveStyle { NoCurve = -1, Lines, Sticks, Steps, Dots, UserCurve = 100 }
Public Member Functions¶
QwtPlotCurve (const QString &title=QString::null)
Protected Member Functions¶
void init ()
Detailed Description¶
A plot item, that represents a series of points.- a) Assign curve properties
- When a curve is created, it is configured to draw black solid lines with in QwtPlotCurve::Lines style and no symbols. You can change this by calling setPen(), setStyle() and setSymbol().
- b) Connect/Assign data.
- QwtPlotCurve gets its points using a QwtSeriesData object offering a bridge to the real storage of the points ( like QAbstractItemModel ). There are several convenience classes derived from QwtSeriesData, that also store the points inside ( like QStandardItemModel ). QwtPlotCurve also offers a couple of variations of setSamples(), that build QwtSeriesData objects from arrays internally.
- c) Attach the curve to a plot
- See QwtPlotItem::attach()
see examples/bode
See also:
QwtPointSeriesData, QwtSymbol,
QwtScaleMap
Member Typedef Documentation¶
typedef QFlags<CurveAttribute> QwtPlotCurve::CurveAttributes¶
Curve attributes.typedef QFlags<LegendAttribute> QwtPlotCurve::LegendAttributes¶
Legend attributes.typedef QFlags<PaintAttribute> QwtPlotCurve::PaintAttributes¶
Paint attributes.Member Enumeration Documentation¶
enum QwtPlotCurve::CurveAttribute Attribute for drawing the curve¶
See also:setCurveAttribute(),
testCurveAttribute(), curveFitter()
- Inverted
- For QwtPlotCurve::Steps only. Draws a step function from the right to the left.
- Fitted
- Only in combination with QwtPlotCurve::Lines A QwtCurveFitter tries to interpolate/smooth the curve, before it is painted.
Curve fitting requires temorary memory for
calculating coefficients and additional points. If painting in
QwtPlotCurve::Fitted mode is slow it might be better to fit the points,
before they are passed to QwtPlotCurve.
enum QwtPlotCurve::CurveStyle Curve styles.¶
See also:setStyle(), style()
- NoCurve
- Don't draw a curve. Note: This doesn't affect the symbols.
- Lines
- Connect the points with straight lines. The lines might be interpolated depending on the 'Fitted' attribute. Curve fitting can be configured using setCurveFitter().
- Sticks
- Draw vertical or horizontal sticks ( depending on the orientation() ) from a baseline which is defined by setBaseline().
- Steps
- Connect the points with a step function. The step function is drawn from the left to the right or vice versa, depending on the QwtPlotCurve::Inverted attribute.
- Dots
- Draw dots at the locations of the data points. Note: This is different from a dotted line (see setPen()), and faster as a curve in QwtPlotCurve::NoStyle style and a symbol painting a point.
- UserCurve
- Styles >= QwtPlotCurve::UserCurve are reserved for derived classes of QwtPlotCurve that overload drawCurve() with additional application specific curve types.
enum QwtPlotCurve::LegendAttribute Attributes how to represent the curve on the legend¶
See also:setLegendAttribute(),
testLegendAttribute(), drawLegendIdentifier()
- LegendNoAttribute
- QwtPlotCurve tries to find a color representing the curve and paints a rectangle with it.
- LegendShowLine
- If the style() is not QwtPlotCurve::NoCurve a line is painted with the curve pen().
- LegendShowSymbol
- If the curve has a valid symbol it is painted.
- LegendShowBrush
- If the curve has a brush a rectangle filled with the curve brush() is painted.
enum QwtPlotCurve::PaintAttribute Attributes to modify the drawing algorithm. The default setting enables ClipPolygons¶
See also:setPaintAttribute(),
testPaintAttribute()
- ClipPolygons
- Clip polygons before painting them. In situations, where points are far outside the visible area (f.e when zooming deep) this might be a substantial improvement for the painting performance
- CacheSymbols
- Paint the symbol to a QPixmap and paint the pixmap instead rendering the symbol for each point. The flag has no effect, when the curve is not painted to the canvas ( f.e when exporting the plot to a PDF document ).
Constructor & Destructor Documentation¶
QwtPlotCurve::QwtPlotCurve (const QString &title = QString::null) [explicit] Constructor¶
Parameters:title Title of the curve
QwtPlotCurve::QwtPlotCurve (const QwtText &title) [explicit] Constructor¶
Parameters:title Title of the curve
QwtPlotCurve::~QwtPlotCurve () [virtual]¶
Destructor.Member Function Documentation¶
double QwtPlotCurve::baseline () const Returns:¶
Value of the baseline
See also:
setBaseline()
const QBrush & QwtPlotCurve::brush () const Returns:¶
Brush used to fill the area between lines and
the baseline
See also:
setBrush(), setBaseline(),
baseline()
void QwtPlotCurve::closePolyline (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, QPolygonF &polygon) const [protected]¶
Complete a polygon to be a closed polygon including the area between the original polygon and the baseline. Parameters:painter Painter
xMap X map
yMap Y map
polygon Polygon to be completed
int QwtPlotCurve::closestPoint (const QPoint &pos, double *dist = NULL) const Find the closest curve point for a specific position¶
Parameters:pos Position, where to look for the
closest curve point
dist If dist != NULL, closestPoint() returns the distance between
the position and the clostest curve point
Returns:
Index of the closest curve point, or -1 if
none can be found ( f.e when the curve has no points )
Note:
closestPoint() implements a dumb
algorithm, that iterates over all points
QwtCurveFitter * QwtPlotCurve::curveFitter () const Get the curve fitter. If curve fitting is disabled NULL is returned.¶
Returns:Curve fitter
See also:
setCurveFitter(), Fitted
void QwtPlotCurve::drawCurve (QPainter *painter, intstyle, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, intfrom, intto) const [protected, virtual]¶
Draw the line part (without symbols) of a curve interval. Parameters:painter Painter
style curve style, see QwtPlotCurve::CurveStyle
xMap x map
yMap y map
canvasRect Contents rect of the canvas
from index of the first point to be painted
to index of the last point to be painted
See also:
draw(), drawDots(),
drawLines(), drawSteps(), drawSticks()
void QwtPlotCurve::drawDots (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, intfrom, intto) const [protected] Draw dots¶
Parameters:painter Painter
xMap x map
yMap y map
canvasRect Contents rect of the canvas
from index of the first point to be painted
to index of the last point to be painted
See also:
draw(), drawCurve(),
drawSticks(), drawLines(), drawSteps()
void QwtPlotCurve::drawLegendIdentifier (QPainter *painter, const QRectF &rect) const [virtual]¶
Draw the identifier representing the curve on the legend. Parameters:painter Painter
rect Bounding rectangle for the identifier
See also:
setLegendAttribute(),
QwtPlotItem::Legend
void QwtPlotCurve::drawLines (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, intfrom, intto) const [protected]¶
Draw lines. If the CurveAttribute Fitted is enabled a QwtCurveFitter tries to interpolate/smooth the curve, before it is painted. Parameters:painter Painter
xMap x map
yMap y map
canvasRect Contents rect of the canvas
from index of the first point to be painted
to index of the last point to be painted
See also:
setCurveAttribute(),
setCurveFitter(), draw(), drawLines(), drawDots(),
drawSteps(), drawSticks()
void QwtPlotCurve::drawSeries (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, intfrom, intto) const [virtual] Draw an interval of the curve¶
Parameters:painter Painter
xMap Maps x-values into pixel coordinates.
yMap Maps y-values into pixel coordinates.
canvasRect Contents rect of the canvas
from Index of the first point to be painted
to Index of the last point to be painted. If to < 0 the curve will be
painted to its last point.
See also:
drawCurve(),
drawSymbols(),
void QwtPlotCurve::drawSteps (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, intfrom, intto) const [protected] Draw step function¶
The direction of the steps depends on Inverted attribute. Parameters:painter Painter
xMap x map
yMap y map
canvasRect Contents rect of the canvas
from index of the first point to be painted
to index of the last point to be painted
See also:
CurveAttribute,
setCurveAttribute(), draw(), drawCurve(),
drawDots(), drawLines(), drawSticks()
void QwtPlotCurve::drawSticks (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, intfrom, intto) const [protected] Draw sticks¶
Parameters:painter Painter
xMap x map
yMap y map
canvasRect Contents rect of the canvas
from index of the first point to be painted
to index of the last point to be painted
See also:
draw(), drawCurve(),
drawDots(), drawLines(), drawSteps()
void QwtPlotCurve::drawSymbols (QPainter *painter, const QwtSymbol &symbol, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, intfrom, intto) const [protected, virtual] Draw symbols¶
Parameters:painter Painter
symbol Curve symbol
xMap x map
yMap y map
canvasRect Contents rect of the canvas
from Index of the first point to be painted
to Index of the last point to be painted
See also:
setSymbol(), drawSeries(),
drawCurve()
void QwtPlotCurve::fillCurve (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, QPolygonF &polygon) const [protected, virtual] Fill the area between the curve and the baseline with the curve brush¶
Parameters:painter Painter
xMap x map
yMap y map
canvasRect Contents rect of the canvas
polygon Polygon - will be modified !
See also:
setBrush(), setBaseline(),
setStyle()
void QwtPlotCurve::init () [protected]¶
Initialize internal members.double QwtPlotCurve::maxXValue () const [inline]¶
boundingRect().right()double QwtPlotCurve::maxYValue () const [inline]¶
boundingRect().bottom()double QwtPlotCurve::minXValue () const [inline]¶
boundingRect().left()double QwtPlotCurve::minYValue () const [inline]¶
boundingRect().top()const QPen & QwtPlotCurve::pen () const Returns:¶
Pen used to draw the lines
See also:
setPen(), brush()
int QwtPlotCurve::rtti () const [virtual] Returns:¶
QwtPlotItem::Rtti_PlotCurve
void QwtPlotCurve::setBaseline (doublevalue)¶
Set the value of the baseline. The baseline is needed for filling the curve with a brush or the Sticks drawing style. The interpretation of the baseline depends on the CurveType. With QwtPlotCurve::Yfx, the baseline is interpreted as a horizontal line at y = baseline(), with QwtPlotCurve::Yfy, it is interpreted as a vertical line at x = baseline(). The default value is 0.0. Parameters:value Value of the baseline
See also:
baseline(), setBrush(),
setStyle(), setStyle()
void QwtPlotCurve::setBrush (const QBrush &brush)¶
Assign a brush. In case of brush.style() != QBrush::NoBrush and style() != QwtPlotCurve::Sticks the area between the curve and the baseline will be filled. In case !brush.color().isValid() the area will be filled by pen.color(). The fill algorithm simply connects the first and the last curve point to the baseline. So the curve data has to be sorted (ascending or descending). Parameters:brush New brush
See also:
brush(), setBaseline(),
baseline()
void QwtPlotCurve::setCurveAttribute (CurveAttributeattribute, boolon = true) Specify an attribute for drawing the curve¶
Parameters:attribute Curve attribute
on On/Off
/sa testCurveAttribute(), setCurveFitter()
void QwtPlotCurve::setCurveFitter (QwtCurveFitter *curveFitter) Assign a curve fitter¶
The curve fitter 'smooths' the curve points, when the Fitted CurveAttribute is set. setCurveFitter(NULL) also disables curve fitting. The curve fitter operates on the translated points ( = widget coordinates) to be functional for logarithmic scales. Obviously this is less performant for fitting algorithms, that reduce the number of points. For situations, where curve fitting is used to improve the performance of painting huge series of points it might be better to execute the fitter on the curve points once and to cache the result in the QwtSeriesData object. Parameters:curveFitter() Curve
fitter
See also:
Fitted
void QwtPlotCurve::setLegendAttribute (LegendAttributeattribute, boolon = true) Specify an attribute how to draw the legend identifier¶
Parameters:attribute Attribute
on On/Off /sa testLegendAttribute()
void QwtPlotCurve::setPaintAttribute (PaintAttributeattribute, boolon = true) Specify an attribute how to draw the curve¶
Parameters:attribute Paint attribute
on On/Off
See also:
testPaintAttribute()
void QwtPlotCurve::setPen (const QPen &pen) Assign a pen¶
Parameters:pen New pen
See also:
pen(), brush()
void QwtPlotCurve::setRawSamples (const double *xData, const double *yData, intsize)¶
Initialize the data by pointing to memory blocks which are not managed by QwtPlotCurve. setRawSamples is provided for efficiency. It is important to keep the pointers during the lifetime of the underlying QwtCPointerData class. Parameters:xData pointer to x data
yData pointer to y data
size size of x and y
See also:
QwtCPointerData
void QwtPlotCurve::setSamples (const QVector< QPointF > &samples) Initialize data with an array of points (explicitly shared).¶
Parameters:samples Vector of points
void QwtPlotCurve::setSamples (const QVector< double > &xData, const QVector< double > &yData)¶
Initialize data with x- and y-arrays (explicitly shared) Parameters:xData x data
yData y data
See also:
QwtPointArrayData
void QwtPlotCurve::setSamples (const double *xData, const double *yData, intsize) Set data by copying x- and y-values from specified memory blocks. Contrary to setRawSamples(), this function makes a 'deep copy' of the data.¶
Parameters:xData pointer to x values
yData pointer to y values
size size of xData and yData
See also:
QwtPointArrayData
void QwtPlotCurve::setStyle (CurveStylestyle) Set the curve's drawing style¶
Parameters:style Curve style
See also:
style()
void QwtPlotCurve::setSymbol (const QwtSymbol *symbol) Assign a symbol¶
Parameters:symbol Symbol
See also:
symbol()
QwtPlotCurve::CurveStyle QwtPlotCurve::style () const Return the current style¶
See also:setStyle()
const QwtSymbol * QwtPlotCurve::symbol () const Returns:¶
Current symbol or NULL, when no symbol has
been assigned
See also:
setSymbol()
bool QwtPlotCurve::testCurveAttribute (CurveAttributeattribute) const Returns:¶
true, if attribute is enabled
See also:
setCurveAttribute()
bool QwtPlotCurve::testLegendAttribute (LegendAttributeattribute) const¶
Return the current paint attributes. See also:setLegendAttribute()
bool QwtPlotCurve::testPaintAttribute (PaintAttributeattribute) const¶
Return the current paint attributes. See also:setPaintAttribute()
void QwtPlotCurve::updateLegend (QwtLegend *legend) const [virtual]¶
Update the widget that represents the item on the legend. Parameters:legend Legend
See also:
drawLegendIdentifier(),
legendItem(), QwtPlotItem::Legend
Author¶
Generated automatically by Doxygen for Qwt User's Guide from the source code.| Fri Apr 15 2011 | Version 6.0.0 |