Running the Example▲
To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.
Using Polar Charts in Qt Quick Applications▲
We begin with a chart that has a spline series and a scatter series with random data. Both series use the same axes.
Sélectionnez
PolarChartView {
title: "Two Series, Common Axes"
anchors.fill: parent
legend.visible: false
antialiasing: true
ValueAxis {
id: axisAngular
min: 0
max: 20
tickCount: 9
}
ValueAxis {
id: axisRadial
min: -0.5
max: 1.5
}
SplineSeries {
id: series1
axisAngular: axisAngular
axisRadial: axisRadial
pointsVisible: true
}
ScatterSeries {
id: series2
axisAngular: axisAngular
axisRadial: axisRadial
markerSize: 10
}
}
// Add data dynamically to the series
Component.onCompleted: {
for (var i = 0; i <= 20; i++) {
series1.append(i, Math.random());
series2.append(i, Math.random());
}
}The next example shows a chart with some accurate historical data for which we need to use a DateTimeAxis and a AreaSeries.
Sélectionnez
PolarChartView {
title: "Historical Area Series"
anchors.fill: parent
legend.visible: false
antialiasing: true
DateTimeAxis {
id: axis1
format: "yyyy MMM"
tickCount: 13
}
ValueAxis {
id: axis2
}
LineSeries {
id: lowerLine
axisAngular: axis1
axisRadial: axis2
// Please note that month in JavaScript months are zero based, so 2 means March
XYPoint { x: toMsecsSinceEpoch(new Date(1950, 0, 1)); y: 15 }
XYPoint { x: toMsecsSinceEpoch(new Date(1962, 4, 1)); y: 35 }
XYPoint { x: toMsecsSinceEpoch(new Date(1970, 0, 1)); y: 50 }
XYPoint { x: toMsecsSinceEpoch(new Date(1978, 2, 1)); y: 75 }
XYPoint { x: toMsecsSinceEpoch(new Date(1987, 11, 1)); y: 102 }
XYPoint { x: toMsecsSinceEpoch(new Date(1992, 1, 1)); y: 132 }
XYPoint { x: toMsecsSinceEpoch(new Date(1998, 7, 1)); y: 100 }
XYPoint { x: toMsecsSinceEpoch(new Date(2002, 4, 1)); y: 120 }
XYPoint { x: toMsecsSinceEpoch(new Date(2012, 8, 1)); y: 140 }
XYPoint { x: toMsecsSinceEpoch(new Date(2013, 5, 1)); y: 150 }
}
LineSeries {
id: upperLine
axisAngular: axis1
axisRadial: axis2
// Please note that month in JavaScript months are zero based, so 2 means March
XYPoint { x: toMsecsSinceEpoch(new Date(1950, 0, 1)); y: 30 }
XYPoint { x: toMsecsSinceEpoch(new Date(1962, 4, 1)); y: 55 }
XYPoint { x: toMsecsSinceEpoch(new Date(1970, 0, 1)); y: 80 }
XYPoint { x: toMsecsSinceEpoch(new Date(1978, 2, 1)); y: 105 }
XYPoint { x: toMsecsSinceEpoch(new Date(1987, 11, 1)); y: 125 }
XYPoint { x: toMsecsSinceEpoch(new Date(1992, 1, 1)); y: 160 }
XYPoint { x: toMsecsSinceEpoch(new Date(1998, 7, 1)); y: 140 }
XYPoint { x: toMsecsSinceEpoch(new Date(2002, 4, 1)); y: 140 }
XYPoint { x: toMsecsSinceEpoch(new Date(2012, 8, 1)); y: 170 }
XYPoint { x: toMsecsSinceEpoch(new Date(2013, 5, 1)); y: 200 }
}
AreaSeries {
axisAngular: axis1
axisRadial: axis2
lowerSeries: lowerLine
upperSeries: upperLine
}
}
// DateTimeAxis is based on QDateTimes so we must convert our JavaScript dates to
// milliseconds since epoch to make them match the DateTimeAxis values
function toMsecsSinceEpoch(date) {
var msecs = date.getTime();
return msecs;
}And the final example with a chart that uses a CategoryAxis to make the data easier to understand.
Sélectionnez
PolarChartView {
title: "Numerical Data for Dummies"
anchors.fill: parent
legend.visible: false
antialiasing: true
LineSeries {
axisRadial: CategoryAxis {
min: 0
max: 30
CategoryRange {
label: "critical"
endValue: 2
}
CategoryRange {
label: "low"
endValue: 7
}
CategoryRange {
label: "normal"
endValue: 12
}
CategoryRange {
label: "high"
endValue: 18
}
CategoryRange {
label: "extremely high"
endValue: 30
}
}
axisAngular: ValueAxis {
tickCount: 13
}
XYPoint { x: 0; y: 4.3 }
XYPoint { x: 1; y: 4.1 }
XYPoint { x: 2; y: 4.7 }
XYPoint { x: 3; y: 3.9 }
XYPoint { x: 4; y: 5.2 }
XYPoint { x: 5; y: 5.3 }
XYPoint { x: 6; y: 6.1 }
XYPoint { x: 7; y: 7.7 }
XYPoint { x: 8; y: 12.9 }
XYPoint { x: 9; y: 19.2 }
}
}