Visualize This, 2nd Edition

Ch.3Handling Data

Before you work on the visual part of any visualization, you need data. Data makes a visualization interesting and worthwhile. Without data, you just have empty charts. That's no fun. Where can you find good data? How can you access it?

Once you have data, you need to format it so that it loads with your software. Maybe you got the data as a comma-delimited text file or an Excel spreadsheet, and you need to convert it to something such as XML, or vice versa. Maybe the data is accessible online spread out over many pages but you want a unified spreadsheet.

Learn where to find data, how to prepare data, and how to process data. Get all your data in order, and the visual part of visualization gets much easier.

DATA PREPARATIONS

Those who are interested in learning more about visualization are often, understandably, focused only on the visual part of the practice. The stuff they see—geometry, color, and patterns—draws them in. However, you need worthwhile data to make worthwhile visualization. Garbage data leads to garbage visualization.

Sometimes, the interesting datasets are given to you, and you get to play right away, but often, the data you need doesn't exist yet or isn't in a format that's useful for your purposes. There's a process behind finding this data and preparing it so that you can more easily visualize it.

I used to work in a restaurant kitchen. My job was to prepare all the ingredients: cleaning, chopping, tenderizing, and marinating. It all ...