Qml Axes

We begin with a chart that has a line series and a scatter series with random data. Both series use the same axes.


  ChartView {
      title: "Two Series, Common Axes"
      anchors.fill: parent
      legend.visible: false
      antialiasing: true

      ValueAxis {
          id: axisX
          min: 0
          max: 10
          tickCount: 5
      }

      ValueAxis {
          id: axisY
          min: -0.5
          max: 1.5
      }

      LineSeries {
          id: series1
          axisX: axisX
          axisY: axisY
      }

      ScatterSeries {
          id: series2
          axisX: axisX
          axisY: axisY
      }
  }

  // Add data dynamically to the series
  Component.onCompleted: {
      for (var i = 0; i <= 10; i++) {
          series1.append(i, Math.random());
          series2.append(i, Math.random());
      }
  }

The next example shows a chart with some accurate historical data that makes us to use a DateTimeAxis.


  ChartView {
      title: "Accurate Historical Data"
      anchors.fill: parent
      legend.visible: false
      antialiasing: true

      LineSeries {
          axisX: DateTimeAxis {
              format: "yyyy MMM"
              tickCount: 5
          }
          axisY: ValueAxis {
              min: 0
              max: 150
          }

          // Please note that month in JavaScript months are zero based, so 2 means March
          XYPoint { x: toMsecsSinceEpoch(new Date(1950, 2, 15)); y: 5 }
          XYPoint { x: toMsecsSinceEpoch(new Date(1970, 0, 1)); y: 50 }
          XYPoint { x: toMsecsSinceEpoch(new Date(1987, 12, 31)); y: 102 }
          XYPoint { x: toMsecsSinceEpoch(new Date(1998, 7, 1)); y: 100 }
          XYPoint { x: toMsecsSinceEpoch(new Date(2012, 8, 2)); y: 110 }
      }
  }

  // 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.


  ChartView {
      title: "Numerical Data for Dummies"
      anchors.fill: parent
      legend.visible: false
      antialiasing: true

      LineSeries {
          axisY: CategoryAxis {
              min: 0
              max: 30
              CategoryRange {
                  label: "critical"
                  endValue: 2
              }
              CategoryRange {
                  label: "low"
                  endValue: 4
              }
              CategoryRange {
                  label: "normal"
                  endValue: 7
              }
              CategoryRange {
                  label: "high"
                  endValue: 15
              }
              CategoryRange {
                  label: "extremely high"
                  endValue: 30
              }
          }

          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 }
      }
  }

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