Working with Vector Data - Desktop GIS: Mapping the Planet with Open Source Tools - page 26

Chapter 3

Working with Vector Data

In this chapter, we'll start working with vector data (points, lines, poly-
gons) by viewing, editing, and analyzing various datasets. Not only will
we view data, but we'll look at tweaking the way data is displayed to
make it convey more information at a glance.

3.1 Viewing Data

Viewing data is like the “Hello, World!” application that everyone writes
when learning a new programming language. It's the first thing you're
going to want to do with any GIS application. Let's start out by seeing
what kind of things we can do with vector data using open source GIS
software. If you recall Harrison's original project, he first just wanted to
view bird locations. We'll take a similar approach and start by viewing
some sample vector data.

Viewing data is really more like visualizing the relationships between
the features. You can get a lot of information by simply viewing features
and applying some special rendering techniques.

When it comes to software, we have a lot of choices for viewing GIS data
(see Appendix A , on page 269 ) . As we begin to explore our data, we'll
use several different applications to give you a feel for what's available.

Before we can begin, we obviously need some data to work with. If
you don't have a shapefile or two handy, you can download 1 a sample
dataset and use it to follow along. We will be using this dataset through-
out the following chapters when we need to illustrate some basic func-
tions or concepts. The dataset includes world borders, cities, and a nice