This topic explains, with code examples, how to use the StackedAreaSeries in the XamDataChart™ control.
The topic is organized as follows:
Stacked Area Series belongs to a group of Category Series and it is rendered using a collection of points connected by line segments (StackedFragmentSeries) with the area below the line filled in and stacked on top of each other. Each stacked fragment in the collection represents one visual element in each stack. Each stack can contain both positive and negative values. All positive values are grouped on the positive side of the y-axis, and all negative values are grouped on the negative side of the y-axis. For more conceptual information, comprehension with other types of series, and supported types of axes, refer to the Category Series and Chart Axes topics.
Figure 1 demonstrates how the StackedAreaSeries looks when plotted in the XamDataChart control.
Figure 1: Sample implementation of the StackedAreaSeries type.
Although the XamDataChart supports plotting unlimited number of various types of series, it is recommended to use the StackedAreaSeries with similar types of series. Refer to the Multiple Series topic for information on what types of series are recommended with the StackedAreaSeries and how to plot multiple types of series.
While the XamDataChart control allows you to easily bind it to your own data model, be sure to supply the appropriate amount and type of data that the series requires. If the data does not meet the minimum requirements based on the type of series that you are using, an error is generated by the control. Refer to the Series Requirements and Category Series topics for more information on data series requirements.
The following is a list of data requirements for the StackedAreaSeries type:
The data model must contain at least one numeric data column. It is recommended that the data model contain two or more numeric data columns so that each point of the StackedAreaSeries has two or more stacked fragments.
The data model may contain an optional string or date time field for labels.
The Stacked Area Series renders data using the following rules:
A StackedFragmentSeries needs be added to the Series collection property of the StackedAreaSeries for every numeric column in the data model that you want rendered.
Each row in the data model represents a single stacked area polygon. Sections are created based on the columns in the data model that are mapped to the ValueMemberPath property of StackedFragmentSeries objects.
When the second value in the row is rendered, its value will be added to the points of the previous values in that row. Therefore, each point going upwards on the chart is a cumulative sum of the values at that point.
The string or date time column that is mapped to the Label property of data mapping on the x-axis is used as the category labels. If the data mapping for Label is not specified, default labels are used.
Category labels are drawn on the x-axis. Data values are drawn on the y-axis.
When rendering, multiple series of the StackedAreaSeries type is rendered in layers with each successive series rendered in front of the previous one in the Series collection of the XamDataChart control. For more information on this feature, refer to the Multiple Series topic.
The code snippet below shows how to bind the StackedAreaSeries object to sample of category data (which is available for download from Sample Energy Data resource). Refer to the data requirements section of this topic for information about data requirements for the StackedAreaSeries.
In XAML:
xmlns:local="clr-namespace:[DATA_MODEL_NAMESPACE]"
In XAML:
<ig:XamDataChart x:Name="DataChart" >
<ig:XamDataChart.Resources>
<local:EnergyProductionDataSample x:Key="energyProdData" />
</ig:XamDataChart.Resources>
<ig:XamDataChart.Axes>
<ig:NumericYAxis x:Name="YAxis" MinimumValue="0" Interval="400" Label="{}{} TWh" />
<ig:CategoryXAxis x:Name="XAxis" ItemsSource="{StaticResource energyProdData}" Label="{}{Country}" />
</ig:XamDataChart.Axes>
<ig:XamDataChart.Series>
<!-- ========================================================================== -->
<ig:StackedAreaSeries XAxis="{Binding ElementName=XAxis}"
YAxis="{Binding ElementName=YAxis}"
ItemsSource="{StaticResource energyProdData}">
<ig:StackedAreaSeries.Series>
<ig:StackedFragmentSeries ValueMemberPath="Coal" Title="Coal" />
<ig:StackedFragmentSeries ValueMemberPath="Hydro" Title="Hydro" />
<ig:StackedFragmentSeries ValueMemberPath="Nuclear" Title="Nuclear" />
<ig:StackedFragmentSeries ValueMemberPath="Gas" Title="Gas" />
<ig:StackedFragmentSeries ValueMemberPath="Oil" Title="Oil" />
</ig:StackedAreaSeries.Series>
</ig:StackedAreaSeries>
</ig:XamDataChart.Series>
<!-- ========================================================================== -->
</ig:XamDataChart>
In Visual Basic:
Dim dataSample As New EnergyProductionDataSample()
Dim yAxis As New NumericYAxis()
Dim xAxis As New CategoryXAxis()
xAxis.DataSource = dataSample
xAxis.Label = "Country"
xAxis.ItemsSource = dataSample
xAxis.Label = "{Country}"
Me.DataChart.Axes.Add(xAxis)
Me.DataChart.Axes.Add(yAxis)
‘ create a stack fragment for each numeric column in your data
Dim seriesFragment As New StackedFragmentSeries()
seriesFragment.ValueMemberPath = "Coal"
seriesFragment.Title = "Coal"
...
Dim series As New StackedAreaSeries()
series.ItemsSource = dataSample
series.DataSource = dataSample
series.XAxis = xAxis
series.YAxis = yAxis
‘ add all stack fragments to the series
series.Series.Add(seriesFragment)
...
Me.DataChart.Series.Add(series)In C#:
EnergyProductionDataSample dataSample = new EnergyProductionDataSample();
NumericYAxis yAxis = new NumericYAxis();
CategoryXAxis xAxis = new CategoryXAxis();
xAxis.DataSource = dataSample;
xAxis.Label = "Country";
xAxis.ItemsSource = dataSample;
xAxis.Label = "{Country}";
this.DataChart.Axes.Add(xAxis);
this.DataChart.Axes.Add(yAxis);
// create a stack fragment for each numeric column in your data
StackedFragmentSeries seriesFragment = new StackedFragmentSeries();
seriesFragment.ValueMemberPath = "Coal";
seriesFragment.Title = "Coal";
...
StackedAreaSeries series = new StackedAreaSeries();
series.ItemsSource = dataSample;
series.DataSource = dataSample;
series.XAxis = xAxis;
series.YAxis = yAxis;
// add all stack fragments to the series
series.Series.Add(seriesFragment);
...
this.DataChart.Series.Add(series);