Trend lines are an invaluable tool in data analysis. We’ll explain how to add them to Power BI visuals to give your report viewers a quick way to tell how things are trending. While not all chart or graph types in Power BI support trend lines there are some workarounds to re-create the look of them that are fairly quick and easy to implement.
Trend lines are a vital component for predictive analysis and measuring business performance. They help people identify long term trends and look beyond the variability in short term data. We’ll explain how to enable and format them, along with highlighting some other techniques that come in handy for trend analysis.
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What are Trend Lines in Power BI?
Trend lines are linear regression lines that can be added to a number of visuals in Power BI to allow report viewers to see long term trends. They are often layered over scatter plots or line charts for an additional level of detail. While the feature is easy to enable, it is not available on all visualization types.
Trend lines are available to add in the following Power BI Visuals:
- Scatter Plots
- Line Charts
- Area Charts
The creation of trend lines is not supported using combination charts, such as line and stacked column charts, If you do not see the option available, it is likely that the chart type does not support trend lines.
How to Add a Trend Line in Power BI
To add a trend line in Power BI, select a scatter plot, line chart or area chart. Then navigate to the “Add Further Analysis” section of the Visualizations panel noted by the magnifying glass with a chart inside of it. Toggle the Trend Line option on. Expand the option for additional formatting options.
Here’s a breakdown with more detail.
Select an appropriate visual – not all visual types support trend lines. If the option is available a Trend line selection will be available under the Add Further Analysis to Your Visual section.
Configure Trend Line Formatting – After enabling the trend line, a line will be added to the visual that you currently have selected. The trend line will automatically adjust when using slicers and filters.
You’ll also notice that additional types of analysis are available, such as the ability to add in constant, min and max lines. There are also some great ways to forecast in Power BI that can help your reports go from being backwards look to forward looking.
Why is there no Trendline Option in Power BI?
Unlike some other tools, Power BI doesn’t offer a direct trendline option for all chart types. This limitation is primarily due to the nature of the data visualization and the complexity involved in calculating trend lines for certain types of data. However, you can often find workarounds, such as layering multiple chart types on top of eachother.
Adding Trend Lines to Visuals that Don’t Support It
Even though Power BI does not support a trend line visual in all visual types, there is a workaround.
The example below is a line chart with a trend line enabled that is layered over a bar chart. Power BI does not natively support this functionality but it can be recreated by placing one chart with a transparent background over another chart.
This method can be highly effective but does take some fine tuning to get visuals to align as expected and to be robust enough not to throw off the presentation when report viewers are using slicers.
Understanding the Trend Line Equation in Power BI
The trend line equation in Power BI is a mathematical representation of the trend shown in your data. It’s typically in the form of a linear equation (y = mx + b), where ‘m’ is the slope, and ‘b’ is the y-intercept. This equation helps in understanding the relationship between variables and predicting future values.
Unfortunately, at the time of writing there is no option to add the trend line equation to a visual. However, it is possible to calculate a linear regression using DAX in Power BI.
How to Draw a Target Line in Power BI
To add a static goal line in Power BI, select a graph or chart. Then navigate to the “Add Further Analysis” section of the Visualizations panel noted by the magnifying glass with a chart inside of it. Toggle the Constant Line option on. Expand the option to assign the value for the straight line and adjust additional formatting options.
In addition to the constant line and trend line in Power BI there are a wide range of additional trend, and forecasting options available.
Trend, Forecasting, and Analysis Options for Power BI Visuals
Power BI supports a wide range of trend, forecasting and analysis lines which are all available by selecting a visual and navigating to the “Add further analysis to your visual” section of the Visualizations Panel. The options available are dynamic and adjust based on the type of visualization. For example, it would not make sense to add a min or max line to a Matrix visual.
The example below is a screenshot of the forecast, trend and analysis options available for the line chart. It has the widest support for various options.
One of the more interesting features that Power BI has added, is the ability to find anomalies. The concept typically comes from the data science world, but power BI takes the work and science out of it by providing a no code way to take advantage of this advanced technique.
If you’re interested in trending in Power BI, check out the following YouTube video from the Guys in a Cube to learn more!
Power BI makes adding trend lines quick and easy by selecting an appropriate visual and navigating to the Analysis Panel and turning Trend Line on. You can adjust formatting to meet your needs.
The options available in the analysis panel of Power BI vary based on the visual selected. If you don’t see the option available it’s likely that the visual type doesn’t support trend lines. When this occurs, one workaround could be adding a line chart over the top of another chart type, disable the background color and adjust the sizing of the chart to match the one below it.