Series.Spline

The Chart Canvas element's Series child elements cause a data visualization (the chart) to be rendered in the canvas. This topic discusses the Series.Spline element.

 

About Series.Spline

The Series.Spline element generates a Spline chart, which is commonly used to represent aggregated totals, as numbers or percentages, over time. It's similar to a Line chart but plots a fitted curve through the data points.
 

 

The example above shows a simple Spline chart, representing sales per month for a year.

 

As shown above, the chart is created by adding Series.Spline to the canvas, along with a datalayer and, typically, some child elements that may include Time Period Column elements, a Group Filter, and a Group Aggregate Column element. Very few attributes need to be set for the Series element in order to produce a basic chart.

Note that a datalayer element can be used either beneath Series.Spline, as shown above, or beneath Chart Canvas. If used as a child of Chart Canvas, its data is available to all child Series elements. This can improve performance if you have several series, all using the same data, beneath the same Chart Canvas element.  

The properties of the X- and Y-axis, including captions, are set using the X-Axis and Y-Axis elements. For example, in order to angle the X-axis labels, add an X-Axis element beneath Chart Canvas (none of its attributes need to be set) and add its child Label Style element. Set the Label Style element's attribute as shown above.

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Using Multiple Series

You can add additional series to the chart by adding additional Series elements:  

The example above shows three Series, one for each year, with a legend.  

The example above shows the three Series elements, their datalayers, the X- and Y-Axis elements, and the Legend element used to produce the previous chart. You can adjust which series appears "in front" of the others in the chart by changing the order of the Series elements in the definition. Setting the Series elements' Legend Label attribute will automatically cause the legend to be displayed.

When using multiple series, you may be able to reduce the number of data queries and improve performance by using local data to read all of the data once, see Datalayer Introduction. Then, link its datalayer to share it to the series, see Link Datalayers. At each Series element, link its datalayer to the shared Local Data datalayer and filter the data to meet the needs of each individual series.

You can combine different types of Series elements, for example, Series.Spline and Series.Bar, to produce combinations of visualizations.
 

In order to produce the legend shown in the previous example, a Legend element must be added and its attributes configured as shown above.

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Attributes

The Series.Spline element has the following attributes:
 

AttributeDescription
Y-Axis Data Column (Required) Specifies the name of a datalayer column whose values will be plotted along the Y-axis.
Color Sets the line color. Enter a color by name, decimal RGB value, or hex RGB value. Prefix hex values with the pound sign, e.g. #112233. @Chart tokens may be used here to provide dynamic, data-driven line segment colors.
Combine With Series ID Set this attribute to the element ID of another series to combine it with this series in the legend. When two series are combined, by default only the first one will appear in the legend but clicking the item in the legend toggles both series to appear and disappear. Or, the value Previous can be entered to combine this series with the previous series.
Connect Nulls Specifies if data rows with null or blank values are to be ignored, allowing adjacent values to be connected in the chart. The default value is False.
Disable Mouse Tracking Disables mouse tracking for the series, when set to True. This affects tooltips and click events on graphs and points. For large datasets, this may improve performance.
The default value is False.
Hover Line Thickness Sets the thickness of the line, in pixels, when the mouse pointer is hovered over it. The default value is 1 pixel.
Legend Label Indicates text that will be shown for this series inside the chart legend. When a value is provided, automatically causes the legend to be displayed.
Line Style Specifies the pattern of the line as either Solid or a combination of dashes and dots. @Chart tokens may be used here to provide dynamic, data-driven line segment styles.
Line ThicknessSpecifies the thickness of the line, in pixels. The default value is 1 pixel.
Linked to X-Axis ID Specifies the ID of an X-Axis element that this series should be linked to when using multiple X-axes.
Linked to Y-Axis ID Specifies the ID of a Y-Axis element that this series should be linked to when using multiple Y-axes.
Negative Color Sets the color for negative values. Enter a color by name, decimal RGB value, or hex RGB value. Prefix hex values with the pound sign, e.g. #D5F484. The default value is Red.
Negative Color Transparency Specifies the transparency of the Negative Color. The lowest value of 0 specifies that the background is opaque, with no transparency. At the other end of the scale, 15 specifies a completely transparent background. Use medium-level transparency to allow different chart layers to show through each other.
Negative ThresholdSets the positive-negative value threshold, also called the "zero level" or "base level". The default value is 0.
Transparency Specifies the transparency of the line color. The lowest value of 0 specifies that the background is opaque, with no transparency. At the other end of the scale, 15 specifies a completely transparent background. Use medium-level transparency to allow different chart layers to show through each other.
X-Axis Data ColumnSpecifies the name of a datalayer column whose values will be plotted along the X-axis.
X-Axis Data Column Type Specifies the data type of the datalayer column named in the X-axis Data Column attribute. Options include Auto (the default), Text, Number, and DateTime. By default, X-axis data values that are DateTime type will be automatically distributed evenly across the time series. If you want to disable this behavior, set this attribute value to Text.

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Using the Data Labels Element

A "data label" is text shown next to each data point that shows its value. When the Data Labels element is used as a child of Series.Spline, text representing the data values will appear on the chart:
 

The Data Labels element has attributes that allow you to control the font family, color, size, and weight, the data format, border color, and positioning of the text. The Data Labels element's color-related attribute values can be set using @Chart tokens.

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Using the Marker Points Element

A "marker point" is a symbol that appears on the chart at each data point. When the Marker Points element is used as a child of Series.Spline, a small dot matching the color of the line will be displayed at each data point:
 

The default marker points are shown above. The Marker Points element allows you to select a different symbol for the marker point, and to control its size, color, border color, and transparency. When the cursor hovers over a marker point, it's automatically enlarged slightly.

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Using the Quicktips Element

By default, a "quicktip" is displayed when the mouse hovers near or over a data point:  

The automatically-generated quicktip displays information for the X- and Y-axis, as shown above, left. However, you may want to display other information or format it differently, perhaps as shown above, right, which can be done by adding a Quicktip child element beneath Series.Spline and setting its attributes and child elements. Use @Chart tokens to include chart data in the quicktip. Intrinsic functions are supported in the Quicktip attributes.

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Using the Trend Line Element

The Trend Line element creates a line on the chart that indicates the "trend" of the data. The line connects a number of data points generated using a regression algorithm.
 

The Trend Line element is a child of the Series.Spline element and can be styled for color, line width, etc. When configured with a legend label, it will be represented by an item in the legend, as shown above.

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Using Action Elements

Action elements initiate processing of a report or process task definition, redirection to a link, or other processing when a data point in the series is clicked.
 

In the example above, an Action.Report element has been added as a child of the Series, along with its Target.Report and Link Parameters child elements. To reference chart data in parameters, use the @Chart token, as shown above. A variety of Action elements are available for use with Series, including Action.Link, Action.Process, and Action.Refresh Element. Additional Action elements will be added in future releases.

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Using Input Selection

This series can also be used with the Input Selection family of elements, which turn the chart into an input control. This allows users, at runtime, to select points or values on the chart with their mouse and your report can then take action using the selected data. This is very useful, for example, for drilling into the data. For more information about this functionality, see Input Selection.

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Using the Refresh Series Timer

The Refresh Series Timer, added as a Series child element, updates charts automatically, based on a time interval. When the interval is reached, a request is sent back to the web server for updated data. Series are updated with a smooth animation.  

The Refresh Interval attribute specifies the number of seconds to wait before refreshing the series data. A value is required and must be an integer greater than 0.
 

Refresh Mode

Series may be refreshed in two ways: either all of the data is refreshed with each request, or the series data automatically slides to the left one data interval per refresh. The refresh mode is selected in the Chart X Axis element's Axis Type attribute. When the Axis Type is not set to DateTimeLinear, all of the data will be refreshed.

When the Axis Type value is DateTimeLinear, newer values are added to the right side of the chart, previous values slide left, and older values disappear as they reach the left edge of the chart. In this case, the Refresh Series Timer element's Time Span attribute is used to specify the age of the data included. This value must be in hh:mm:ss format (for example "00:02:00" for two minutes) and must be larger than the Refresh Interval attribute value.

When a Time Span attribute is set, the series' datalayer can make use of a special timestamp token, @Chart.rdTimeSpanStart~, in a query to retrieve just the rows necessary to update the chart. On the initial request, this token returns the current time minus the Time Span value. For subsequent refreshes, when Axis Type = DateTimeLinear and the X-axis will be sliding, the token returns the last time the chart was updated, so only the newest rows are retrieved. Here's an MS SQL Server query example:

    SELECT * FROM MyTable WHERE UpdateTime BETWEEN '@Chart.rdTimeSpanStart~' AND '@Function.DateTime~'

For best performance, avoid setting a very short refresh interval if a very large number of users will be displaying the report.

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