Book Image

Learning Geospatial Analysis with Python

By : Joel Lawhead
Book Image

Learning Geospatial Analysis with Python

By: Joel Lawhead

Overview of this book

Geospatial Analysis is used in almost every field you can think of from medicine, to defense, to farming. This book will guide you gently into this exciting and complex field. It walks you through the building blocks of geospatial analysis and how to apply them to influence decision making using the latest Python software. Learning Geospatial Analysis with Python, 2nd Edition uses the expressive and powerful Python 3 programming language to guide you through geographic information systems, remote sensing, topography, and more, while providing a framework for you to approach geospatial analysis effectively, but on your own terms. We start by giving you a little background on the field, and a survey of the techniques and technology used. We then split the field into its component specialty areas: GIS, remote sensing, elevation data, advanced modeling, and real-time data. This book will teach you everything you need to know about, Geospatial Analysis from using a particular software package or API to using generic algorithms that can be applied. This book focuses on pure Python whenever possible to minimize compiling platform-dependent binaries, so that you don’t become bogged down in just getting ready to do analysis. This book will round out your technical library through handy recipes that will give you a good understanding of a field that supplements many a modern day human endeavors.
Table of Contents (17 chapters)
Learning Geospatial Analysis with Python Second Edition
About the Author
About the Reviewers

Parsing the GPX

Now, we'll parse the GPX file, which is just XML, using the built-in xml.dom.minidom module. We'll extract the latitude, longitude, elevation, and timestamps. We'll store them in a list for later use. The timestamps are converted to struct_time objects using Python's time module, which makes them easier to work with:

# Parse the gpx file and extract the coordinates"Parsing GPX file: {}".format(gpx))
xml = minidom.parse(gpx)
# Grab all of the "trkpt" elements
trkpts = xml.getElementsByTagName("trkpt")
# Latitude list
lats = []
# Longitude list
lons = []
# Elevation list
elvs = []
# GPX timestamp list
times = []
# Parse lat/long, elevation and times
for trkpt in trkpts:
    # Latitude
    lat = float(trkpt.attributes["lat"].value)
    # Longitude
    lon = float(trkpt.attributes["lon"].value)
    # Elevation
    elv = trkpt.childNodes[0].firstChild.nodeValue
    elv = float(elv)
    # Times
    t = trkpt...