Make Your Java Data More Useful with Treemap Visualization

isualization is all about taking data and turning it into useful information. The technique is glaringly useful and widely used. Consider the following situation: you want to display the profiles of the population of a country, divided by age.

Age Group	Number of People
0-18	1,452,382
18-35	1,231,987
35-50	842,427
50+	692,120

This type of presentation requires more thinking to get a grip on the data than it should. This is the kind of processing that the computer should be doing for you. For instance, the computer could make this easier on the end user by changing the raw figures into percentages.

Age Group	Percentage of Population
0-18	42%
18-35	39%
35-50	11%
50+	8%

	Figure 1: This pie chart represents the data even more accessibly.

The percentages tell a better story. But understanding could be enhanced even further if the data were drawn as a pie-chart, as in Figure 1.

From the size of the slices on the pie, end users can more easily interpret the data and turn it into useful information.

But what happens when you've got a lot of data to visualize? Bar charts and scatter charts, while useful, are limited in the number of data points that they can render.