charts
Line Disjoint Axis Axes Example
Example:
/// Example of using disjoint measure axes to render 4 series of lines with
/// separate scales. The general use case for this type of chart is to show
/// differences in the trends of the data, without comparing their absolute
/// values.
///
/// Disjoint measure axes will be used to scale the series associated with them,
/// but they will not render any tick elements on either side of the chart.
import 'package:charts_flutter/flutter.dart' as charts;
import 'package:flutter/material.dart';
class DisjointMeasureAxisLineChart extends StatelessWidget {
final List<charts.Series> seriesList;
final bool animate;
DisjointMeasureAxisLineChart(this.seriesList, {this.animate});
/// Creates a [LineChart] with sample data and no transition.
factory DisjointMeasureAxisLineChart.withSampleData() {
return new DisjointMeasureAxisLineChart(
_createSampleData(),
// Disable animations for image tests.
animate: false,
);
}
@override
Widget build(BuildContext context) {
return new charts.LineChart(seriesList,
animate: animate,
// Configure a primary measure axis that will render gridlines across
// the chart. This axis uses fake ticks with no labels to ensure that we
// get 5 grid lines.
//
// We do this because disjoint measure axes do not draw any tick
// elements on the chart.
primaryMeasureAxis: new charts.NumericAxisSpec(
tickProviderSpec: new charts.StaticNumericTickProviderSpec(
// Create the ticks to be used the domain axis.
<charts.TickSpec<num>>[
new charts.TickSpec(0, label: ''),
new charts.TickSpec(1, label: ''),
new charts.TickSpec(2, label: ''),
new charts.TickSpec(3, label: ''),
new charts.TickSpec(4, label: ''),
],
)),
// Create one disjoint measure axis per series on the chart.
//
// Disjoint measure axes will be used to scale the rendered data,
// without drawing any tick elements on either side of the chart.
disjointMeasureAxes:
new LinkedHashMap<String, charts.NumericAxisSpec>.from({
'axis 1': new charts.NumericAxisSpec(),
'axis 2': new charts.NumericAxisSpec(),
'axis 3': new charts.NumericAxisSpec(),
'axis 4': new charts.NumericAxisSpec(),
}));
}
/// Create one series with sample hard coded data.
static List<charts.Series<LinearClicks, int>> _createSampleData() {
// The first three series contain similar data with different magnitudes.
// This demonstrates the ability to graph the trends in each series relative
// to each other, without the largest magnitude series compressing the
// smallest.
final myFakeDesktopData = [
new LinearClicks(0, clickCount: 25),
new LinearClicks(1, clickCount: 125),
new LinearClicks(2, clickCount: 920),
new LinearClicks(3, clickCount: 375),
];
final myFakeTabletData = [
new LinearClicks(0, clickCount: 375),
new LinearClicks(1, clickCount: 1850),
new LinearClicks(2, clickCount: 9700),
new LinearClicks(3, clickCount: 5000),
];
final myFakeMobileData = [
new LinearClicks(0, clickCount: 5000),
new LinearClicks(1, clickCount: 25000),
new LinearClicks(2, clickCount: 100000),
new LinearClicks(3, clickCount: 75000),
];
// The fourth series renders with decimal values, representing a very
// different sort ratio-based data. If this was on the same axis as any of
// the other series, it would be squashed near zero.
final myFakeClickRateData = [
new LinearClicks(0, clickRate: .25),
new LinearClicks(1, clickRate: .65),
new LinearClicks(2, clickRate: .50),
new LinearClicks(3, clickRate: .30),
];
return [
// We render an empty series on the primary measure axis to ensure that
// the axis itself gets rendered. This helps us draw the gridlines on the
// chart.
new charts.Series<LinearClicks, int>(
id: 'Fake Series',
domainFn: (LinearClicks clickCount, _) => clickCount.year,
measureFn: (LinearClicks clickCount, _) => clickCount.clickCount,
data: []),
new charts.Series<LinearClicks, int>(
id: 'Desktop',
colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
domainFn: (LinearClicks clickCount, _) => clickCount.year,
measureFn: (LinearClicks clickCount, _) => clickCount.clickCount,
data: myFakeDesktopData,
)
// Set the 'Desktop' series to use a disjoint axis.
..setAttribute(charts.measureAxisIdKey, 'axis 1'),
new charts.Series<LinearClicks, int>(
id: 'Tablet',
colorFn: (_, __) => charts.MaterialPalette.red.shadeDefault,
domainFn: (LinearClicks clickCount, _) => clickCount.year,
measureFn: (LinearClicks clickCount, _) => clickCount.clickCount,
data: myFakeTabletData,
)
// Set the 'Tablet' series to use a disjoint axis.
..setAttribute(charts.measureAxisIdKey, 'axis 2'),
new charts.Series<LinearClicks, int>(
id: 'Mobile',
colorFn: (_, __) => charts.MaterialPalette.green.shadeDefault,
domainFn: (LinearClicks clickCount, _) => clickCount.year,
measureFn: (LinearClicks clickCount, _) => clickCount.clickCount,
data: myFakeMobileData,
)
// Set the 'Mobile' series to use a disjoint axis.
..setAttribute(charts.measureAxisIdKey, 'axis 3'),
new charts.Series<LinearClicks, int>(
id: 'Click Rate',
colorFn: (_, __) => charts.MaterialPalette.purple.shadeDefault,
domainFn: (LinearClicks clickCount, _) => clickCount.year,
measureFn: (LinearClicks clickCount, _) => clickCount.clickRate,
data: myFakeClickRateData,
)
// Set the 'Click Rate' series to use a disjoint axis.
..setAttribute(charts.measureAxisIdKey, 'axis 4'),
];
}
}
/// Sample linear data type.
class LinearClicks {
final int year;
final int clickCount;
final double clickRate;
LinearClicks(this.year, {this.clickCount = null, this.clickRate = null});
}