Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Save more on your purchases now! discount-offer-chevron-icon
Savings automatically calculated. No voucher code required.
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Python Geospatial Analysis Cookbook

You're reading from   Python Geospatial Analysis Cookbook Over 60 recipes to work with topology, overlays, indoor routing, and web application analysis with Python

Arrow left icon
Product type Paperback
Published in Nov 2015
Publisher
ISBN-13 9781783555079
Length 310 pages
Edition 1st Edition
Languages
Arrow right icon
Toc

Table of Contents (15) Chapters Close

Preface 1. Setting Up Your Geospatial Python Environment FREE CHAPTER 2. Working with Projections 3. Moving Spatial Data from One Format to Another 4. Working with PostGIS 5. Vector Analysis 6. Overlay Analysis 7. Raster Analysis 8. Network Routing Analysis 9. Topology Checking and Data Validation 10. Visualizing Your Analysis 11. Web Analysis with GeoDjango A. Other Geospatial Python Libraries
B. Mapping Icon Libraries
Index

Finding the Dijkstra shortest path with pgRouting


There are a few Python libraries out there, such as networkX and scikit-image, that can find the shortest path over a raster or NumPy array. We want to focus on routing over a vector source and returning a vector dataset; therefore, pgRouting is a natural choice for us. Custom Python Dijkstra or the A Star (A*) shortest path algorithms exist but one that performs well on large networks is hard to find. The pgRouting extension of PostgreSQL is used by OSM and many other projects and is well tested.

Our example will have us load a Shapefile of an indoor network from one floor for simplicity's sake. An indoor network is comprised of network lines that go along the hallways and open walkable spaces within a building, leading to a door in most cases.

Getting ready

For this recipe, we are going to need to set up our PostGIS database with the pgRouting extension. On a Windows machine, you can install pgRouting by downloading a ZIP file for Postgresql...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $19.99/month. Cancel anytime