Tecnologia

Visualizing Data

Ben Fry

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Visualizing Data
by Ben Fry
Copyright © 2008 Ben Fry. All rights reserved. Printed in the United States of America. Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472. O’Reilly books may be purchased for educational, business, or sales promotionaluse. Online editions are also available for most titles (safari.oreilly.com). For more information, contact our corporate/institutional sales department: (800) 998-9938 or corporate@oreilly.com.

Editor: Andy Oram Production Editor: Loranah Dimant Copyeditor: Genevieve d’Entremont Proofreader: Loranah Dimant Printing History:
December 2007: First Edition.

Indexer: Ellen Troutman Zaig CoverDesigner: Karen Montgomery Interior Designer: David Futato Illustrator: Jessamyn Read

Nutshell Handbook, the Nutshell Handbook logo, and the O’Reilly logo are registered trademarks of O’Reilly Media, Inc. Visualizing Data, the image of an owl, and related trade dress are trademarks of O’Reilly Media, Inc. Many of the designations used by manufacturers and sellers to distinguish their products areclaimed as trademarks. Where those designations appear in this book, and O’Reilly Media, Inc. was aware of a trademark claim, the designations have been printed in caps or initial caps. While every precaution has been taken in the preparation of this book, the publisher and author assume no responsibility for errors or omissions, or for damages resulting from the use of the information containedherein.

This book uses RepKover™ a durable and flexible lay-flat binding. , ISBN-10: 0-596-51455-7 ISBN-13: 978-0-596-51455-6 [C]

Table of Contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii 1. The Seven Stages of Visualizing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 1
Why Data Display Requires Planning An Example Iteration and Combination Principles Onward 2 6 14 15 18

2. Getting Started with Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Sketching with Processing Exporting and Distributing Your Work Examples and Reference Functions Sketching and Scripting Ready? 20 23 24 27 28 30

3. Mapping . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Drawing a Map Locations on a Map Data on a Map Using Your Own Data Next Steps 31 32 34 51 53

iii

4. Time Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Milk, Tea, and Coffee (Acquire and Parse) Cleaning the Table(Filter and Mine) A Simple Plot (Represent and Refine) Labeling the Current Data Set (Refine and Interact) Drawing Axis Labels (Refine) Choosing a Proper Representation (Represent and Refine) Using Rollovers to Highlight Points (Interact) Ways to Connect Points (Refine) Text Labels As Tabbed Panes (Interact) Interpolation Between Data Sets (Interact) End of the Series 55 55 57 59 62 73 76 77 83 8792

5. Connections and Correlations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Changing Data Sources Problem Statement Preprocessing Using the Preprocessed Data (Acquire, Parse, Filter, Mine) Displaying the Results (Represent) Returning to the Question (Refine) Sophisticated Sorting: Using Salary As a Tiebreaker (Mine) Moving to Multiple Days (Interact)Smoothing Out the Interaction (Refine) Deployment Considerations (Acquire, Parse, Filter) 94 95 96 111 118 121 126 127 132 133

6. Scatterplot Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Preprocessing Loading the Data (Acquire and Parse) Drawing a Scatterplot of Zip Codes (Mine and Represent) Highlighting Points While Typing (Refine...