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

Showing statistics with colors


How the map is colorized is only a matter of defining the limits and colors in the style. So, if we want to translate statistical information into colors, we just need to associate the values that we want with a sequence of colors.

First, let's try it with the quartiles:

  1. Since everything is prepared in our class, we just need to change the code in the if __name__ == '__main__': block:

    if __name__ == '__main__':
        dem = RasterData('output/dem.tif')
        shaded = RasterData('output/shaded.png')
        limits = [dem.stats['Q1'],
                  dem.stats['Q3'],
                  dem.stats['Maximum']]
        colors = ["#fc8d59", "#ffffbf", "#91cf60"]
        dem.colorize(limits, colors).write_image('output/stats.png')
        dem.alpha_blend(shaded).write_image('output/shaded_stats.png')

    The following image illustrates the colored output for the analyzed parameters:

    For this image you can start the lead-in this way:

Using the histogram to colorize the image

We can also use the histogram...