Often, you will want to compare the differences of measured values across different dimensions. You might find yourself asking questions like these:
How much profit did I generate in each department?
How many views did each of my websites get?
How many cases did each doctor in the hospital treat last year?
In each case, you are looking to make a comparison (among departments, websites, or doctors) in terms of some quantitative measurement (profit, number of views, and the count of cases).
Here is a simple bar chart, created using the Superstore Sales data source, similar to the one we built in Chapter 1, Creating Your First Visualizations and Dashboard:
The sum of sales is easily compared for each category of item sold in the chain of stores. Category is used as a discrete dimension in the view, which defines row headers (because it is discrete) and slices the sum of sales for each category (because it is a dimension). Sales defines an axis...