In my previous blog, I had posted a bar chart showing declining trend in sales of a company over the years. If you notice, it had a trend line to aid visual analytics.
Another example given below shows profit trends by increase in sales for each category.
Trend lines are great visual tools for quick analysis. In the above diagram, its very easy to judge that the increase in sales for Supplies and Tables does not help increasing profit. The same judgement could not have been derived that easy from the clustered circles if the trend lines were not present. The steps to add Trend Lines are explained below.
I have created a scatter plot for Sales vs Profit using the Global Superstore database. Notice the “analytics” tab highlighted below.
Drag ‘Trend Line’ from the options to the visualization area and choose the line type. In this example, I have selected Linear model.
Additional options are available at (Right click -> Trend Lines-> Edit Trend Lines). For example, you can choose to show only one line (uncheck show trend line per color) and view for each category interactively for focused view/analysis as shown below