Introduction

Up to now our style of interacting with gnuplot has mainly been to have an interactive conversation at the terminal, or to create a linear sequence of commands that can be read in and executed by typing gnuplot file. We went beyond this a bit in the previous chapter, where we learned how to arrange for a document preparation system to invoke gnuplot automatically. In this chapter, we shall learn how to leverage the full power of gnuplot as a programmable graphing engine. This is made possible by gnuplot's design as a program that can be completely controlled by textual commands, rather than by a limited graphical user interface. This means that any programming language that can send text to a process or socket can send commands to gnuplot. The result is that there are libraries for interfacing with gnuplot in almost every high-level programming or scripting language, and even in cases where no library is available it is straightforward to communicate manually from within your...