QPolarChart Class | Qt Charts 5.8

Qt 5.8 | Qt Charts | C++ Classes | QPolarChart

Qt 5.8.0 Reference Documentation

# QPolarChart Class

Polar chart API for Qt Charts. More...

Header: | #include <QPolarChart>
Inherits: | QChart

- List of all members, including inherited members

## Public Types

enum | PolarOrientation { PolarOrientationRadial, PolarOrientationAngular }
flags | PolarOrientations

## Public Functions

| QPolarChart(QGraphicsItem *parent = Q_NULLPTR, Qt::WindowFlags wFlags = Qt::WindowFlags())
| ~QPolarChart()
void | addAxis(QAbstractAxis *axis, PolarOrientation polarOrientation)
QList<QAbstractAxis *> | axes(PolarOrientations polarOrientation = PolarOrientations( PolarOrientationRadial | PolarOrientationAngular ), QAbstractSeries *series = Q_NULLPTR) const

- 60 public functions inherited from QChart
- 53 public functions inherited from QGraphicsWidget
- 35 public functions inherited from QGraphicsLayoutItem
- 2 public functions inherited from QGraphicsObject
- 176 public functions inherited from QGraphicsItem

## Static Public Members

PolarOrientation | axisPolarOrientation(QAbstractAxis *axis)

- 1 static public member inherited from QGraphicsWidget

### Additional Inherited Members

- 14 properties inherited from QChart
- 14 properties inherited from QGraphicsWidget
- 12 properties inherited from QGraphicsObject
- 1 public slot inherited from QGraphicsWidget
- 1 signal inherited from QChart
- 1 signal inherited from QGraphicsWidget
- 9 signals inherited from QGraphicsObject
- 1 public variable inherited from QGraphicsWidget
- 2 public variables inherited from QGraphicsItem
- 24 protected functions inherited from QGraphicsWidget
- 3 protected functions inherited from QGraphicsLayoutItem
- 1 protected function inherited from QGraphicsObject
- 24 protected functions inherited from QGraphicsItem
- 1 protected slot inherited from QGraphicsObject
- 1 protected type inherited from QGraphicsLayoutItem
- 1 protected type inherited from QGraphicsItem

## Detailed Description

Polar chart API for Qt Charts.

QPolarChart is a specialization of QChart to show a polar chart.

Polar charts support line, spline, area, and scatter series, and all axis types supported by those series.

Note: When setting ticks to an angular QValueAxis, keep in mind that the first and last tick are co-located at 0/360 degree angle.

Note: If the angular distance between two consecutive points in a series is more than 180 degrees, any line connecting the two points becomes meaningless, so choose the axis ranges accordingly when displaying line, spline, or area series. In such case series don't draw a direct line between the two points, but instead draw a line to and from the center of the chart.

Note: Polar charts draw all axes of same orientation in the same position, so using multiple axes of same orientation can be confusing, unless the extra axes are only used to customize the grid (e.g. you can display a highlighted range with a secondary shaded QCategoryAxis or provide unlabeled subticks with a secondary QValueAxis that has its labels hidden).

See also QChart.

## Member Type Documentation

### enum QPolarChart::PolarOrientation
flags QPolarChart::PolarOrientations

This type is used to specify the polar orientation of an axis.

Constant | Value
--- | ---
`QPolarChart::PolarOrientationRadial` | `0x1`
`QPolarChart::PolarOrientationAngular` | `0x2`

The PolarOrientations type is a typedef for QFlags<PolarOrientation>. It stores an OR combination of PolarOrientation values.

## Member Function Documentation

### QPolarChart::QPolarChart(QGraphicsItem *parent = Q_NULLPTR, Qt::WindowFlags wFlags = Qt::WindowFlags())

Constructs a polar chart as a child of the parent. Parameter wFlags is passed to the QChart constructor.

### QPolarChart::~QPolarChart()

Destroys the polar chart object and its children, like series and axis objects added to it.

### void QPolarChart::addAxis(QAbstractAxis *axis, PolarOrientation polarOrientation)

This convenience method adds axis to the polar chart with polarOrientation. The chart takes the ownership of the axis.

Note: Axes can be added to a polar chart also with QChart::addAxis() instead of this method. The specified alignment determines the polar orientation: horizontal alignments indicate angular axis and vertical alignments indicate radial axis.

See also QChart::removeAxis(), QChart::createDefaultAxes(), QAbstractSeries::attachAxis(), and QChart::addAxis().

### QList<QAbstractAxis *> QPolarChart::axes(PolarOrientations polarOrientation = PolarOrientations( PolarOrientationRadial | PolarOrientationAngular ), QAbstractSeries *series = Q_NULLPTR) const

Returns the axes added for the series with polarOrientation. If no series is provided, then any axis with the specified polar orientation is returned.

See also addAxis().

### `[static]` PolarOrientation QPolarChart::axisPolarOrientation(QAbstractAxis *axis)

Angular axes of a polar chart report horizontal orientation and radial axes report vertical orientation. This function is a convenience function for converting the orientation of an axis to corresponding polar orientation. If the axis is NULL or not added to a polar chart, the return value is meaningless.