Book Image

Python Geospatial Development - Third Edition

By : Erik Westra
Book Image

Python Geospatial Development - Third Edition

By: Erik Westra

Overview of this book

Geospatial development links your data to locations on the surface of the Earth. Writing geospatial programs involves tasks such as grouping data by location, storing and analyzing large amounts of spatial information, performing complex geospatial calculations, and drawing colorful interactive maps. In order to do this well, you’ll need appropriate tools and techniques, as well as a thorough understanding of geospatial concepts such as map projections, datums, and coordinate systems. This book provides an overview of the major geospatial concepts, data sources, and toolkits. It starts by showing you how to store and access spatial data using Python, how to perform a range of spatial calculations, and how to store spatial data in a database. Further on, the book teaches you how to build your own slippy map interface within a web application, and finishes with the detailed construction of a geospatial data editor using the GeoDjango framework. By the end of this book, you will be able to confidently use Python to write your own geospatial applications ranging from quick, one-off utilities to sophisticated web-based applications using maps and other geospatial data.
Table of Contents (20 chapters)
Python Geospatial Development Third Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Summary


In this chapter, we finished implementing a sophisticated geospatial web application using GeoDjango, Mapnik, PostGIS, OGR, and pyproj. This application is useful in its own right as well as being a springboard to developing your own geospatial web applications.

We learned that we can easily create our own Tile Map Server using Mapnik and GeoDjango. We saw how to use OpenLayers in our own web pages and how OpenLayers can be made to work with our Tile Map Server. We learned how to intercept mouse clicks using OpenLayers and how to use JQuery's AJAX functionality to send requests to the server for processing.

We then saw how to use Proj.4 to calculate a search radius measured in degrees of latitude and longitude and how to use GeoDjango's query functions to identify features close to the point where the user clicked. We also looked at how to use GeoDjango's editing forms to let the user view and edit the contents of a geometry.

Finally, we saw how to handle the addition of new features...