Book Image

QGIS 2 Cookbook

By : Mandel, Olaya Ferrero, Anita Graser
Book Image

QGIS 2 Cookbook

By: Mandel, Olaya Ferrero, Anita Graser

Overview of this book

QGIS is a user-friendly, cross-platform desktop geographic information system used to make maps and analyze spatial data. QGIS allows users to understand, question, interpret, and visualize spatial data in many ways that reveal relationships, patterns, and trends in the form of maps. This book is a collection of simple to advanced techniques that are needed in everyday geospatial work, and shows how to accomplish them with QGIS. You will begin by understanding the different types of data management techniques, as well as how data exploration works. You will then learn how to perform classic vector and raster analysis with QGIS, apart from creating time-based visualizations. Finally, you will learn how to create interactive and visually appealing maps with custom cartography. By the end of this book, you will have all the necessary knowledge to handle spatial data management, exploration, and visualization tasks in QGIS.
Table of Contents (14 chapters)
13
Index

Configuring data-defined labels

If there was a list of top features of QGIS, data-defined labels would be high on that list. They offer the ease of automatic labeling with the customization of freehand labeling. You can mix and match automatic and custom edits, storing the values in a table for later reference.

Getting ready

There are a couple of useful plugins for data-defined labeling which will add the extra attribute fields that you need to either an existing layer or make a new layer just for labels. Download and install Layer to labeled layer and Create labeled layer.

How to do it…

  1. Open QGIS and load census_wake2000.shp.
  2. Create a copy of the layer using the Save As dialog, and save the layer as census_wake2000_label.shp. (You don't always have to do this but this process does modify the table, so it's a good idea to make a backup.)
  3. Highlight census_wake2000_label.shp in the layer list.
  4. Run the Layer to labeled layer plugin (Plugins | Layer to Labeled layer plugin):
    1. Set Label...