Qml Axes | Qt Charts 5.15.18

- Qt 5.15
- Qt Charts
- Qt Charts Examples
- Qml Axes
- Qt Charts | Commercial or GPLv3

# Qml Axes

This is a demonstration of how to use axes in your QML application.

#### 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 Axes in Qt Quick Applications

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 }
         }
     }

Example project @ code.qt.io