Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By : Joel Lawhead
Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By: Joel Lawhead

Overview of this book

QGIS is a desktop geographic information system that facilitates data viewing, editing, and analysis. Paired with the most efficient scripting language—Python, we can write effective scripts that extend the core functionality of QGIS. Based on version QGIS 2.18, this book will teach you how to write Python code that works with spatial data to automate geoprocessing tasks in QGIS. It will cover topics such as querying and editing vector data and using raster data. You will also learn to create, edit, and optimize a vector layer for faster queries, reproject a vector layer, reduce the number of vertices in a vector layer without losing critical data, and convert a raster to a vector. Following this, you will work through recipes that will help you compose static maps, create heavily customized maps, and add specialized labels and annotations. As well as this, we’ll also share a few tips and tricks based on different aspects of QGIS.
Table of Contents (16 chapters)
QGIS Python Programming Cookbook - Second Edition
About the Author
About the Reviewer
Customer Feedback

Visualizing multitemporal data

The vast majority of GIS maps are a static slice in time or summary totals of a period of time. But there are many geospatial formats capable of storing time series data. In this recipe, we'll load a dataset that has multiple time steps, and use the well-designed TimeManager plugin to step through the data time steps in an animation. The dataset we're using is a collection of global earthquake data from 2011 totaled by month. You can see an animation of the output of this recipe online at the following URL. The data loops through each month and renders the earthquake location and magnitude here:

Getting ready

You will need to install the QGIS Python TimeManager plugin by Anita Graser and Karolina Alexioufor this exercise. From the QGIS Plugins menu, select Manage and Install Plugins.... In the Plugins dialog search box, search for TimeManager. Select TimeManager plugin and click on the Install plugin...