Matplotlib for Python Developers

Sandro Tosi

• Publisher: Packt Publishing
• Year: 2009
• ISBN:
  9781847197900
• Edition: 1
• Topic: Computer Science
• Subtopic: Information Technology
• Index: Computer Science

In Detail

Providing appealing plots and graphs is an essential part of various fields such as scientific research, data analysis, and so on. Matplotlib, the Python 2D plotting library, is used to produce publication-quality figures in a variety of hardcopy formats and interactive environments across platforms. This book explains creating various plots, histograms, power spectra, bar charts, error charts, scatter-plots and much more using the powerful Matplotlib library to get impressive out-of-the-box results.

This book gives you a comprehensive tour of the key features of the Matplotlib Python 2D plotting library, right from the simplest concepts to the most advanced topics. You will discover how easy it is to produce professional-quality plots when you have this book to hand.

The book introduces the library in steps. First come the basics: introducing what the library is, its important prerequisites (and terminology), installing and configuring Matplotlib, and going through simple plots such as lines, grids, axes, and charts. Then we start with some introductory examples, and move ahead by discussing the various programming styles that Matplotlib allows, and several key features.

Further, the book presents an important section on embedding applications. You will be introduced to three of the best known GUI libraries-GTK+, Qt, and wxWidgets-and presented with the steps to implement to include Matplotlib in an application written using each of them. You will learn through an incremental approach: from a simple example that presents the peculiarities of the GUI library, to more complex ones, using GUI designer tools.

Because the Web permeates all of our activities, a part of the book is dedicated to showing how Matplotlib can be used in a web environment, and another section focuses on using Matplotlib with common Python web frameworks, namely, Pylons and Django. Last, but not least, you will go through real-world examples, where you will see some real situations in which you can use Matplotlib.

This book is a step-by-step tutorial to the Python 2D plotting library Matplotlib, which teaches you from the ground up to advanced levels with plenty of examples, code, and images.

Approach

This is a practical, hands-on book, with a lot of code and images. It presents the real code that generates every image and describes almost every single line of it, so that you know exactly what's going on.

Introductory, descriptive, and theoretical parts are mixed with examples, so that reading and understanding them is easy. All of the examples build gradually with code snippets, their explanations, and plot images where necessary with the complete code and output presented at the end.

Who this book is for

This book is essentially for Python developers who have a good knowledge of Python; no knowledge of Matplotlib is required. You will be creating 2D plots using Matplotlib in no time at all.

Matplotlib for Python Developers

Sandro Tosi

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Table of Contents

Matplotlib for Python Developers

Credits

About the Author

About the Reviewers

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Errata

Piracy

Questions

1. Introduction to Matplotlib

Merits of Matplotlib

Matplotlib web sites and online documentation

Output formats and backends

Output formats

Backends

About dependencies

Build dependencies

Installing Matplotlib

Installing Matplotlib on Linux

Installing Matplotlib on Windows

Installing Matplotlib on Mac OS X

Installing Matplotlib using packaged Python distributions

Installing Matplotlib from source code

Testing our installation

Summary

2. Getting Started with Matplotlib

First plots with Matplotlib

Multiline plots

A brief introduction to NumPy arrays

Grid, axes, and labels

Adding a grid

Handling axes

Adding labels

Titles and legends

Adding a title

Adding a legend

A complete example

Saving plots to a file

Interactive navigation toolbar

IPython support

Controlling the interactive mode

Suppressing functions output

Configuring Matplotlib

Configuration files

Configuring through the Python code

Selecting backend from code

Summary

3. Decorate Graphs with Plot Styles and Types

Markers and line styles

Control colors

Specifying styles in multiline plots

Control line styles

Control marker styles

Finer control with keyword arguments

Handling X and Y ticks

Plot types

Histogram charts

Error bar charts

Bar charts

Pie charts

Scatter plots

Polar charts

Navigation Toolbar with polar plots

Control radial and angular grids

Text inside figure, annotations, and arrows

Text inside figure

Annotations

Arrows

Summary

4. Advanced Matplotlib

Object-oriented versus MATLAB styles

A brief introduction to Matplotlib objects

Our first (simple) example of OO Matplotlib

Subplots

Multiple figures

Additional Y (or X) axes

Logarithmic axes

Share axes

Plotting dates

Date formatting

Axes formatting with axes tick locators and formatters

Custom formatters and locators

Text properties, fonts, and LaTeX

Fonts

Using LaTeX formatting

Mathtext

External TeX renderer

Contour plots and image plotting

Contour plots

Image plotting

Summary

5. Embedding Matplotlib in GTK+

A brief introduction to GTK+

Introduction to GTK+ signal system

Embedding a Matplotlib figure in a GTK+ window

Including a navigation toolbar

Real-time plots update

Embedding Matplotlib in a Glade application

Designing the GUI using Glade

Code to use Glade GUI

Summary

6. Embedding Matplotlib in Qt 4

Brief introduction to Qt 4 and PyQt4

Embedding a Matplotlib figure in a Qt window

Including a navigation toolbar

Real-time update of a Matplotlib graph

Embedding Matplotlib in a GUI made with Qt Designer

Designing the GUI using Qt Designer

Code to use the Qt Designer GUI

Introduction to signals and slots

Returning to the example

Summary

7. Embedding Matplotlib in wxWidgets

Brief introduction to wxWidgets and wxPython

Embedding a Matplotlib figure in a wxFrame

Including a navigation toolbar

Real-time plots update

Embedding Matplotlib in a GUI made with wxGlade

Summary

8. Matplotlib for the Web

Matplotlib and CGI

What is CGI

Configuring Apache for CGI execution

Simple CGI example

Matplotlib in a CGI script

Passing parameters to a CGI script

Matplotlib and mod_python

What is mod_python

Apache configuration for mod_python

Matplotlib in a mod_python example

Matplotlib and mod_python's Python Server Pages

Web Frameworks and MVC

Matplotlib and Django

What is Django

Matplotlib in a Django application

Matplotlib and Pylons

What is Pylons

Matplotlib in a Pylons application

Summary

9. Matplotlib in the Real World

Plotting data from a database

Plotting data from the Web

Plotting data by parsing an Apache log file

Plotting data from a CSV file

Plotting extrapolated data using curve fitting

Tools using Matplotlib

NetworkX

Mpmath

Plotting geographical data

First example

Using satellite background

Plot data over a map

Plotting shapefiles with Basemap

Summary

Index

Matplotlib for Python Developers

Copyright © 2009 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, Packt Publishing, nor its dealers or distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: November 2009

Production Reference: 2221009

Published by Packt Publishing Ltd. 32 Lincoln Road Olton Birmingham, B27 6PA, UK.

ISBN 978-1-847197-90-0

www.packtpub.com

Cover Image by Raghuram Ashok (<[email protected]>)

Credits

Author

Sandro Tosi

Reviewers

Michael...