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

Creating a simple routing network


In this recipe, we will create a routing network from scratch using the QGIS editing tools. Even though more and more open network data is available, there will still be numerous use cases where necessary network data does not exist or is not available for use. Therefore, it is good to know how to create a network and what to pay attention to in order to avoid common pitfalls.

For the task of network creation, the main difference between the Road graph plugin and pgRouting is that pgRouting needs a network node (that is, link start or end node) at each intersection while the Road graph plugin will also use intermediate link geometry nodes to infer intersections if two links share a node. In this recipe, we will create a network, which can be used in both tools.

Getting ready

To follow this recipe, you only need a new empty QGIS project. Additionally, make sure you have the Digitizing toolbar enabled (as shown in the following screenshot). We will create an...