Chapter 4. Practical matters

In the previous two chapters, we looked at ways to manipulate and visualize data using gnuplot, which is the core task that gnuplot was designed for. Before moving on to more sophisticated application areas, let’s close this introductory part of the book by looking at some features of gnuplot that don’t directly have much to do with data and visualization, but that are useful to have around.

First, we’ll learn how to view and manipulate options, which are gnuplot’s way of controlling details of its operation. Then we’ll summarize what we’ve learned about input file formats and show how we can use options to customize some aspects of file handling. From files, it’s only a small step to strings: gnuplot can read strings from files and make them part of a graph. We’ll see how to do this, and learn about gnuplot’s facilities to handle and manipulate strings.

The last part of this chapter talks about useful tricks relating to gnuplot’s interactive terminals. In the process, we’ll also learn how to use gnuplot’s online help system and history feature.

This chapter is a bit of a grab-bag of useful features. What they all have in common is that they help us be more productive with gnuplot, without directly being related to the manipulation and plotting of data. This chapter deals with the “other stuff.”

4.1. Managing options

4.2. Data files

4.3. Strings

4.4. Generating textual output

4.5. Interacting with gnuplot

4.6. Summary