Qml Polar Chart

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.


  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.


  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.


  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 }
      }
  }

Files:

Contents

Qml Polar Chart

Running the Example

Using Polar Charts in Qt Quick Applications