How to use a Time Graph to Tell a Story
Using time to tell a story can be one of the most useful tools in your visualization toolbox. Power BI has the Pulse Chart, among others, that allows you to show key events on a timeline and then animate them with a playback of the events to reveal patterns and insights. No better way to learn about this chart than see it in action, so let’s go through a quick tutorial that will build the visualization.
Great Example of Using Time
This visualization from Bloomberg, the The Hottest Year on Record is a great example of using a Time Animation to tell a story. The animation over time shows exactly what the author intended in a very simple and visual way. The colors are not jarring and change with the intensity of the data. The bar chart at the bottom is a little hidden but perfectly placed not to take away from the main story the author is trying to portray. The most interesting takeaway was the building year by year, showing the average increase as we get to the highest values today.
Being able to tell a story with your data and get that point across effectively was well done here. I found that this was a perfect visualization example for the trend over time of the temperature data. We can use time to tell a story in Power BI with such visualizations as the Pulse Chart.
What are Pulse Charts?
Power BI has a gallery of visuals you can bring into Dashboards. The Pulse chart is a custom visual and not in the out-of-the-box visualizations. The Pulse chart allows you to show key events on a timeline and then animate them with a playback of the events to reveal patterns and insights. No better way to learn about this chart than see it in action, so let’s go through a quick tutorial that will build the following visualization.
Highlighting when the Daily Count its a multiple of 500 as a Highlighted Events
How to Tell a Story over Time
The data point was to show the increase in the rate of cases over the time of the outbreak. As you see from the above visualization, an event occurs as a multiple of 500 case threshold is broken. As time moves on, the numbers get larger, but what can be misses is the rate of increase in the daily case count. By having an event occur each time a barrier is broken, the points are close together as the cases arise. As time goes on, the rate at which the case multiple of 500 is broken speeds up. Tells more of the story than just having the line chart.
Power BI Pulse Chart – Tutorial
Step 1 – Find the Pulse Chart and add it to Power BI
Once you have opened a new Power BI Book in Power BI Desktop, you will see 3 dots (1) under at the end of the visualization panel. Which when you select, this will bring up a search dialogue. Type in Pulse (2), which will filter the list to the Pulse Chart and select Add (3). to add the chart to the selection.
Step 2 – Create the Data Source
I created and Excel file from a CSV, pictured below. You need to have a Date to use as the timestamp, a value, and Events, if you want to show events.
Once you have imported the data, the Pulse Chart takes the following elements shown in the below capture.
Step 3 – Populate the Fields
Populating the data fields is fairly straight forward. You will however, find that there are many options that you can have making this a very flexible visualization.
- The Timestamp is the dates that cover the data set you are working with
- The Values are what the line is drawn to
- The Event title is the event text you want to show
- Event Description is a title on the event popup you wish to
- The Event Size is a numerical value you can provide that will control the dot’s size that is shown when the event is displayed.
- The Runner Counter will adjust what is displayed in the top right counter when the chart animates.
Step 4 – Settings and Formatting
Okay, so in the previous step, I mentioned that there were many display options; the amount of visual formatting and customization seems endless. Below I have put in the full set of formatting options on the right and have called out the Playback settings on the right. I found those change quite a bit depending on the data.
Wrapping UP
I can often get lost in the number of visualizations and even fail to see new ones that come out. Go through the gallery of visuals and see what is new and what you might find interesting. Just throw data into excel and doing a quick Power Bi visualization, and see what you can add to your toolbox.
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