Book Image

Geospatial Development By Example with Python

By : Pablo Carreira
5 (1)
Book Image

Geospatial Development By Example with Python

5 (1)
By: Pablo Carreira

Overview of this book

From Python programming good practices to the advanced use of analysis packages, this book teaches you how to write applications that will perform complex geoprocessing tasks that can be replicated and reused. Much more than simple scripts, you will write functions to import data, create Python classes that represent your features, and learn how to combine and filter them. With pluggable mechanisms, you will learn how to visualize data and the results of analysis in beautiful maps that can be batch-generated and embedded into documents or web pages. Finally, you will learn how to consume and process an enormous amount of data very efficiently by using advanced tools and modern computers’ parallel processing capabilities.
Table of Contents (17 chapters)
Geospatial Development By Example with Python
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Geometry relationships


We want to filter the geocaching points that fall inside a given boundary (a country, state, city, and so on.). In order to perform this kind of filtering, we need to verify every point and see whether it's inside the polygon representing the boundary.

In geoprocessing, the relations between the two geometries are described by a set of known predicates. These relationships are very important because they allow conditions to be made, so one can perform operations and calculations.

Shapely comes with a complete set of predicates that analyze the relation of the two geometries. Before we go further in our app, let's take a look at the possible relation checks.

Touches

This is true if the geometries have one or more points in common without their interiors intersecting.

Crosses

This is true if there is an intersection between the two objects without one containing the other.

Contains

This indicates if one object completely contains the other object; all the boundaries, lines,...