How to read this book

Stop! Install the current version of plt (see appendix F, beginning on page ) if it is not already installed on your system, or if the version you have already was installed before 26 April 2005. Do this now, then come back here and read on.

This book attempts to be both a tutorial and a reference manual. It describes every plt option, including many that have been undocumented since plt was written in the mid-1980s. Although you can read this book from cover to cover, in most cases you will not need to do so in order to make high-quality plots. plt has a bewildering number of options, but it is very easy to make simple plots using only a small subset of these options.

If you have never used plt before, begin with chapter 2, Getting Started with plt, try out the examples there, and then try making a few plots of your own before continuing. Many readers will not need to go any further.

If you have used earlier versions of plt, you may wish to look first at appendix G, What's New?, for a brief summary of recent changes.

A good strategy for many users is to find in these pages an example that illustrates features you would like to include in your plot, then read the description of how the example was created. In this sense, this book is best used like a cookbook. All of the scripts and data files used to generate these examples are included in the doc subdirectory of the plt distribution (see appendix F).

Chapter 3, Preparing Input for plt, is completely new. Even if you have been using plt for years, you will probably find some surprises here. Chapter 4 is also new; it contains a systematic presentation of the four major coordinate systems (data, window, page, and text) used by plt.

Chapter 5, Titles and Axes, is essential reading if you have not used plt previously. On the other hand, almost no one will need to know everything in chapter 6, Plotting Data, but it is worthwhile to skim through it, so that you will know what is possible.

Chapter 7, Plotting Two or More Data Sets Together, will be helpful if you are trying to create a group of related plots; it offers several ways to accomplish the task of presenting multiple data sets.

Often a few well-chosen text labels can clarify a plot; chapter 8, Labelling Your Plot, shows how to make them. Chapter 9, Drawing Line Segments, Arrows, and Boxes, continues with the related subjects of adding arrows, outlined or shaded boxes, and arbitrary line segments to your plots.

Occasionally you may need to prepare a plot without one or more of the standard elements, such as axes or titles; chapter 10, Suppressing Plot Elements, shows how to do this without using whiteout, as well as how to include data points that fall outside of the axis ranges without inking them in.

Throughout this book are examples that use a variety of line styles, shading, color, and text fonts. Chapter 11, Colors, Line Styles, and Fonts, discusses how to control these aspects of your plots' appearance.

Chapter 12, Advanced Axis Options describes a variety of special-purpose options for fine control over axes, including how to make logarithmic axes and how to create extra labelled axis ticks.

At the end of this book, appendix A, Color Names, contains a complete list of the named colors that can be used for PostScript and X window output. Appendix B, Preparing Printed Output, contains details on creating printed plots on PostScript and other printers, and on embedding plots in L^ATEX documents such as this one. Appendix D, On-Screen Plots, describes how to use plt in an X Window System environment. A few hints on writing shell scripts with plt appear in appendix E, Scripting with plt. Appendix F, How to get and install plt, describes how to obtain plt and how to compile and install it. Appendix G, What's New?, summarizes new features in plt, and includes a (short) list of known bugs. Finally, appendix H reproduces the man page for plt.