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

Loading a NetCDF file

NetCDF stands for Network Common Data Form and is an open geospatial and scientific data format. Features of the format include machine independent data storage, the ability to store vector, raster, and statistical data, as well as multi-dimensional data, and widespread software read and write support. NetCDF is commonly used for meteorological data, which is what we'll use in this example. Loading NetCDF data in QGIS is a little different from the other types of raster data because of its multi-dimensional capability.

Getting ready

Download the sea surface temperature sample NetCDF file from the following URL:

Place that file in your /qgis_data/rasters directory.

How to do it...

  1. In the QGIS Python Console, create a variable for the path or URI for the NetCDF file. Note that we must specify at the beginning that this file is a NetCDF file, and at the end of the URI, we must specify which of the variables...