Gnuplot in Action
Understanding Data with Graphs
Philipp K. Janert
  • August 2009
  • ISBN 9781933988399
  • 396 pages
  • printed in black & white

Knee-deep in data? This is your guidebook to exploring it with gnuplot.

Austin King, Mozilla


Gnuplot in Action, Second Edition is now available. An eBook of this older edition is included at no additional cost when you buy the revised edition!

A limited number of pBook copies of this edition are still available. Please contact Manning Support to inquire about purchasing previous edition copies.

Gnuplot in Action is the first comprehensive introduction to gnuplot—from the basics to the power features and beyond. Besides providing a tutorial on gnuplot itself, it demonstrates how to apply and use gnuplot to extract intelligence from data. Particular attention is paid to tricky or poorly-explained areas. You will learn how to apply gnuplot to actual data analysis problems. This book looks at different types of graphs that can be generated with gnuplot and will discuss when and how to use them to extract actual information from data.

Table of Contents detailed table of contents





about this book

Part 1 Basics

1. Chapter 1 Prelude: Understanding data with gnuplot

1.1. A busy weekend

1.2. What is graphical analysis?

1.3. What is gnuplot?

1.4. Summary

2. Chapter 2 Essential gnuplot

2.1. Simple plots

2.2. Saving and exporting

2.3. Summary

3. Chapter 3 Working with data

3.1. Managing large data sets

3.2. Smoothing and summarizing data

3.3. Math with gnuplot

3.4. Data transformations

3.5. Plotting functions and data

3.6. Logarithmic plots

3.7. Summary

4. Chapter 4 Practical matters

4.1. Managing options

4.2. Data files

4.3. Strings

4.4. Generating textual output

4.5. Interacting with gnuplot

4.6. Summary

Part 2 Polishing

5. Chapter 5 Doing it with style

5.1. Choosing plot styles

5.2. Plot styles

5.3. Customizing styles

5.4. Summary

6. Chapter 6 Decorations

6.1. Quick start: minimal context for data

6.2. Digression: locations on a graph

6.3. Additional graph elements: decorations

6.4. The graph’s legend or key

6.5. Worked example: features of a spectrum

6.6. Overall appearance

6.7. Summary

7. Chapter 7 All about axes

7.1. Multiple axes

7.2. Selecting plot ranges

7.3. Tic marks

7.4. A worked example

7.5. Special case: time series

7.6. Summary

Part 3 Advanced Gnuplot

8. Chapter 8 Three-dimensional plots

8.1. Basics

8.2. Options for surface and contour plots

8.3. Coordinate axes and view point

8.4. Plotting data from a file using splot

8.5. Summary

9. Chapter 9 Color

9.1. Defining palettes

9.2. Creating colored graphs with palettes

9.3. Using color for data representation

9.4. Case studies

9.5. Summary

10. Chapter 10 Advanced plotting concepts

10.1. Multiplot

10.2. Higher math and special occasions

10.3. Curve fitting

10.4. Summary

11. Chapter 11 Terminals in depth

11.1. Exporting graphs to file

11.2. Common terminal options

11.3. Standard graphics file formats

11.4. Print-quality output

11.5. Interactive terminals

11.6. Other terminals

11.7. Summary

12. Chapter 12 Macros, scripting, and batch operations

12.1. Strings and string macros

12.2. Calling other programs from gnuplot

12.3. Calling gnuplot from other programs

12.4. Slideshows with pause and reread

12.5. Configuring your workspace

12.6. Gnuplot for the web

12.7. Summary

Part 4 Graphical Analysis with Gnuplot

13. Chapter 13 Fundamental graphical methods

13.1. Relationships

13.2. Counting statistics

13.3. Ranked data

13.4. Multivariate data

13.5. Summary

14. Chapter 14 Techniques of graphical analysis

14.1. The core principle of graphical analysis

14.2. Iteration and transformation

14.3. Changing the appearance to improve perception

14.4. Housekeeping

14.5. Reminders for presentation graphics

14.6. Summary

Appendix A: Obtaining, building, and installing gnuplot

Appendix B: Gnuplot reference

Appendix C: Resources


© 2014 Manning Publications Co.

About the Technology

Statistical data is only as valuable as your ability to analyze, interpret, and present it in a meaningful way. Gnuplot is the most widely used program to plot and visualize data for Unix/Linux systems and it is also popular for Windows and the Mac. It's open-source (as in free!), actively maintained, stable, and mature. It can deal with arbitrarily large data sets and is capable of producing high-quality, publication-ready graphics.

So far, the only comprehensive documentation available about gnuplot is the online reference documentation, which makes it both hard to get started and almost impossible to get a complete overview over all of its features. If you've never tried gnuplot—or have found it tough to get your arms around—read on.

About the book

One of gnuplot's main advantages is that it requires no programming skills nor knowledge of advanced mathematical or statistical concepts. Gnuplot in Action assumes you have no previous knowledge of either gnuplot or statistics and data analysis. The books starts out with basic gnuplot concepts, then describes in depth how to get a graph ready for final presentation and to make it look "just right" by including arrows, labels, and other decorations.

Next the book looks at advanced concepts, such as multi-dimensional graphs and false-color plots—powerful features for special purposes. The author also describes advanced applications of gnuplot, such as how to script gnuplot so that it can run unattended as a batch job, and how to call gnuplot from within a CGI script to generate graphics for dynamic websites on demand.

What's inside

  • Creating graphs with gnuplot
  • Data transformations and filters
  • Preparing/polishing graphs for final presentation
  • Publishing graphs in print or on the Web
  • Using gnuplot's power features
  • Gnuplot scripting and programming
  • Types of graphs and when to use them
  • Techniques of graphical analysis
  • How to build, install, and develop for gnuplot
  • Command and Option reference organized by concept

About the reader

Gnuplot in Action makes gnuplot easy for anyone who needs to do data analysis, but doesn't have an education in analytical tools and methods. It's perfect for DBAs, programmers, and performance engineers; business analysts and MBAs; and Six-Sigma Black Belts and process engineers.

About the author

Philipp K. Janert is Chief Consultant at Principal Value, LLC. He has been a gnuplot user for more than 15 years and regards it as one of the indispensable tools in his toolbox. He has worked for small start-ups and in large corporate environments, both in the US and overseas, including several years at, where he initiated and led several projects to improve Amazon's order fulfillment processes. Philipp K. Janert has written about software and software development for the O'Reilly Network, IBM developerWorks, IEEE Software, and Linux Magazine. He holds a Ph.D. in Theoretical Physics from the University of Washington. Visit his website at


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Sparkles with insight about visualization, image perception, and data exploration.

Richard B. Kreckel,

Incredibly useful for beginners - indispensable for advanced users.

Mark Pruett, Systems Architect Dominion

Bridges the gap between gnupolt's reference manual and real-world problems.

Mitchell Johnson, Border Stylo

A Swiss Army knife for plotting data.

Nishanth Sastry, Computer Laboratory, University of Cambridge/IBM