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
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Adding a logo to the map


An important part of customizing a map is to add your logo, or other graphics, to the composition. In this recipe, we'll add a simple logo to the map.

Getting ready

You will need to download the following zipped shapefile and extract it to your qgis_data directory in a subdirectory named ms:

https://github.com/GeospatialPython/Learn/raw/master/Mississippi.zip

You will also need a logo image, which you can download from https://github.com/GeospatialPython/Learn/raw/master/logo.png.

Place the image in your qgis_data/rasters directory.

If you haven't already done so in the previous recipe, download the MapComposer library from https://github.com/GeospatialPython/Learn/raw/master/MapComposer.py, to simplify the creation of the map composition.

Place the file in the .qgis2/python directory within your home directory.

How to do it...

In this recipe, we will create the map composition, add the logo image, and save the map as an image. To do this, we need to perform the following...