Time series data are great to clarify the changes over time in measures, and the line chart is the favourite chart for this type of data. But displaying results with a normal line chart can also obscure important patterns, especially if the measure contains some form of seasonality. The cycle plot (first introduced by Cleveland, Dunn, and Terpenning in 1978) is a type of line chart specifically developed to show seasonal time series.
The cycle plot helps you to visualise trends within your seasonal data. It has the strengths of common line charts, without obscuring important cyclical patterns. The cycle plot offers a great deal of flexibility in the choice of your variables: think of months vs. year, hours vs. day or months vs. presidential period.
Let’s illustrate this with an example. Say we are looking at temperatures in a certain city over a few years. We expect that Winters are colder than Summers. Plotting this with a line chart will yield a line with a cyclical pattern: low values in Winter, high values in Summer. However, it’s hard to tell if temperatures in January are increasing or decreasing over the years. With the cycle plot, a subplot can be created for each month, showing the change in temperatures over time for that month. All the subplots together still show the seasonal pattern as well, as seen in the image above.
Key features of the Cycle Plot are:
Show central line: Add a median or average line per subplot, to provide more context to your chart.
Format the objects: Your measurements and central lines can be formatted independently, and supports the theme settings;
The Axis formatting options are in line with the options you know from the Power BI Line Chart, so no need to learn a new interface;
Selection & Highlighting: Like in standard Power BI Charts you can make use of the Selection & Highlighting functions within the Cycle Plot;
Context menu: Like in standard Power BI Charts you have access to the context menu to (amongst others) Drill down and Include/Exclude data points;
Full tooltip support: Besides the default Tooltip behaviour (show the value of the element you hover) you can also add additional fields to the tooltip.
Full Bookmark support: like any of the standard visuals the Cycle Plot supports Bookmarks.
This visual offers in-app purchases and comes with free access to evaluate all features.