Book Image

QGIS 2 Cookbook

By : Alex Mandel, Víctor Olaya Ferrero, Anita Graser, Alexander Bruy
Book Image

QGIS 2 Cookbook

By: Alex Mandel, Víctor Olaya Ferrero, Anita Graser, Alexander Bruy

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 (19 chapters)
QGIS 2 Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

The PostGIS Topology Editor plugin


Maintaining topology in the vector layers is very important; this results in greater data integrity and leads to more accurate analysis results. This recipe shows you how to edit PostGIS topology layers (in other words, layers with topology objects, such as edges, faces, and nodes) with QGIS.

Note

Installation of PostGIS with topology support won't be covered in detail here because instructions for the different operating systems can be found on the project website at http://postgis.net/docs/manual-2.1/postgis_installation.html. If you are using Windows, PostGIS can be installed directly from the Stack Builder application, which is provided by the standard PostgreSQL installation, as described at http://www.bostongis.com/PrinterFriendly.aspx?content_name=postgis_tut01.

Getting ready

To follow this exercise, you need a PostGIS database with topology enabled. In QGIS, you should set up the connection to the database using the New button in the Add PostGIS Layers...