Area Plot

Area plots are suitable for tracking and comparing changes in Data Values over a period of time. An area plot arranges a period horizontally, encodes data values into points, connects them by line, and fills the area below it with a color.

Clustered Area

You could use a clustered area plot to break down data values into subcategories for more granular analysis. For instance, the Clustered Area Demo shows the Net Sales changes over the year divided into clustered areas per product category.

Stacked Area

A stacked area is another way to break down data values into subcategories by placing corresponding area subsections on top of each other. The Stacked Area Demo shows the Net Sales changes over the year divided into stacked areas per product category.

Percentage Stacked Area

A percentage stacked area combines the stacked area and the Percentage axis scale. In addition to changes in data values, it also shows each subcategory's contribution to a total. For instance, the Percentage Stacked Area Demo shows the percentage share of product categories in Net Sales.

You can configure all these types using the Area plot template and its properties described in the following sections. The Area Stacked and Area Percent Stacked templates are just shortcuts to a specific configuration.

You can use the following demos to explore plot properties - open a link, toggle the Report explorer, select the Plot - Plot 1 node and use the Properties panel to modify the configuration.

You could also download the report files listed below and open them in the Standalone Report Designer.

Chart Wizard

If you add a chart into a report, set the plot type to Area on the first page of the Chart Wizard, and click the Next button, the wizard shows the Area Settings page that looks like the following:

Chart Wizard for Area Plots

The Data Values section allows you to add one or more Data Values.

The Data Categories section allows you to set the Category Encoding.

The Data Subcategories section allows you to configure the Details Encoding.

Data Values

The Area plot's Values collection determines data values that change over time. The Chart Wizard displays the Values collection as Fields in the Data Values section. Collection items consist of two properties:

The Value is usually a bound field reference. The Properties Panel displays the Value as the collection, but Line plots take the first item only. The Chart Wizard displays the Value as Field.
The Aggregate is an optional function, such as Count or Average, that reduces many field values into a single one.

For instance, all the demos listed above have the Value={SalesAmount}, Aggregate=Sum Data Value.

Category Encoding

The Category Encoding of an Area plot is a set of properties that determine the period over which the plot generates connected data points representing those above Data Values.

The Category is usually a bound field reference. Bound DataSet Records with the same value of that field fall into the same category. Distinct categories form the period. For instance, all the area plot demos are bound to the Sales DataSet containing several fields, including the SalesDate for each data record. The plot's Category is set to {MonthName(Month(SalesDate))} expression. Therefore the plot goes through the Sales DataSet, finds the distinct months from the SalesDate values, and generates one category per month. If you preview a demo output, you can see 12 months along the horizontal axis.
The Category Sorting configuration determines the order of the category values appearance. For instance, the demo plots have the Category Sort Expression = {Month(SalesDate)}, Category Sort Direction = Ascending settings to ensure chronological order.

The Chart Wizard offers the simplified editor of the Categories Encoding in the Data Categories section:

A single Category Expression displayed as Field is available.
The Sorting configuration of the Category Encoding displays the Sort direction property only. The Sort Expression is automatically set to the same value as the Field property has.

Details Encoding

The Details Encoding allows you to break down those above Data Values into subcategories for more granular analysis of changes.

The Details property of the Area plot is the collection of items that define these subcategories. Each item includes several properties:

The Values is usually one or more bound field references. Bound DataSet Records with the same values of these fields fall into the same subcategory. For instance, in the area demos, the plot Details value is {ProductCategory}. Consequently, the Net Sales area breaks down into multiple subsections corresponding to distinct product categories.
The Exclude Nulls flag indicates whether DataSet Records with an undefined Details Value should be excluded from the visualization.
The Group property determines how the plot arranges area subsections.
- Stack - a plot places area subsections on top of each other. You can use this value to configure a Stacked Area plot.
- Cluster - area subsections overlap each other. The Clustered Area Demo uses this value for the plot details.
- None - equals to Cluster.
The Sorting configuration determines the order of subsections appearance.

The Chart Wizard offers the simplified editor of the Details Encoding in the Data Subcategories section:

A single Details Encoding item is available.
A single Value item displayed as Field is available.
The Group property of the Detail Encoding is displayed as Break-down method.
The Sorting configuration of the Details Encoding displays the Sort direction property only. The Sort Expression is automatically set to the Field value.

Colors Encoding

The Colors Encoding enables the color legend of the Details Encoding and includes the Color expression and the optional Color Aggregate function that reduces many Color values into a single one.

The plot calculates distinct Color Encoding results for the subcategories produced by the Details Encoding, converts them to fill color of corresponding areas, and displays the match between colors and encoding results in the legend. Colors come from the Chart Palette.

For instance, the area plot demos use the {ProductCategory} expression for the Colors Encoding. Consequently, the report output shows the colors legend that matches Product Categories with fill color of corresponding areas.

Note: The Color property is the collection, but the Area plot takes the first item only.

Plot look-and-feel

The following properties allow you to fine-tune the outfit of shapes that form the Area plot. You can see their effect in action by modifying the configuration of any area demo.

The Opacity is a number in percentage that determine the opacity of areas filled with color. 100% means they are opaque, and 0% means that they are entirely transparent.

The Line Aspect property determines the style of the line that connects data points.

Default means the straight line
Spline means the bezier curve
Step Center, Step Left and Step Right mean the stepped line with different step directions.

The Show Nulls property indicates the arrangement of data points for Null values.

Gaps means that the plot will not draw a line between a null data point and its previous and next points
Zero means that null data points will be considered to have 0 value
Connected means that the plot will connect the previous and the next points of a null point

The Clipping Mode indicates the manner that the plot area draws a plot:

Fit value means that the plot area should use all the available space to fit the plot
Clip value means that the plot area cuts off the plot on the edge of its right or bottom padding
None value equals to Fit

The line properties in the Style section determine the appearance of lines that connect data points.

The color expression in the Background section sets the fill color of areas and overwrites the Color Encoding described earlier.

Data points can display labels with the following content that you can set up using the Label Text Template expression.

You can choose one of the following values in the drop-down list.

Value Field Name usually means the field name bound to a Data Value.
Value Field Value means the current Data Value within the containing Category or Details.
Percentage In Details means the percentage share of the current Data Value among all the values with the same Details.
Percentage In Category means the percentage share of the current Data Value among all the values with the same Category.
Category Field Name usually means the field name bound to the Category Encoding.
Category Field Value means the current Category Encoding value.
Details Field Name usually means the field name bound to the Details Encoding.
Details Field Value means the current Details Encoding value.
Color Field Name usually means the field name bound to the Color Encoding.
Color Field Value means the current Color Encoding value.

Also, you could use the template's Expression Editor to set the formatting for these values using the interpolation syntax and supported format strings. For instance, you can set the Label Text Template to {valueField.value:C2} in the Stacked Area Demo to display Net Sales Amount as currency.

Labels Appearance

A subset of text properties in the Label Text section and the line properties in the Label Border section allow you to set up the corresponding visual parameters of the plot labels.

The Label Position and an optional Offset in pixels determine the location of labels relative to a parent data point symbol:

Inside - on the bottom
Outside - on the top
Center - on the center
Auto - equals to Outside

The Overlapping Labels property indicates the handling of overlapping labels. Possible values are:

Auto - hides some labels to prevent the overlapping
Show - shows all labels even if the overlapping persists

The line properties in the Label Line section allows you to add the connecting lines between labels and their parent data points. The Label Line Position determines the connection point of a label's bounding box and the line:

Auto - selected automatically
Center - on the center of the bounding box side

Action

This group of properties determine the Interactive Action when a report reader clicks inside a filled area. You can use bound field references to pass parameters in a drill-through report or configure a dynamic bookmark or URL. The field value is evaluated in the scope of the current detail. Visit the Drill-Through Reports Walkthrough for more information. It explains how to set up the drill-through column plot, but the same technique is applicable for an area plot.