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
About the Authors
About the Reviewers

Calculating the shortest paths using the Road graph plugin

This recipe shows you how to use the built-in Road graph plugin to calculate the shortest paths in a network.

Getting ready

To follow this recipe, load network_pgr.shp from the sample data. Additionally, make sure that the Road graph plugin is enabled in Plugin Manager.

How to do it…

The Road graph plugin enables us to route between two points that are selected on the map. Before we can use this, we have to configure it first, as follows:

  1. Enable the Shortest path panel by navigating to View | Panels. This should add the plugin panel to the user interface.

  2. Go to Vector | Road graph | Settings to get to the configuration dialog. For now, the default settings, as shown in the following screenshot, should be fine. Note that the network layer is selected as Transportation layer. Click on OK to confirm the settings:

  3. Once the settings are configured, we can calculate our first route. Select the Start and Stop locations using the buttons marked...