More often than not, you will want to compare the differences of measured values across different categories. You might find yourself asking questions like this:
- How much profit did we generate in each department?
- How many views did each web page get?
- How many patients did each doctor see?
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 count of patients).
The following figure is a simple bar chart, similar to the one we built in Chapter 1, Creating Your First Visualizations and Dashboards:
The sum of sales is 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 (because it is continuous) and is summed (because it...