This chapter is mostly concerned with ways to tell the different curves apart when multiple functions and/or datasets are plotted on a single graph. The three chief methods of accomplishing this are to plot the curves with different colors, different styles (thin, thick, dashed, dotted, and so on), or by using different types of symbols (or what gnuplot calls points). We saw examples of different line styles in the preceding chapters, and gnuplot will automatically render a series of curves in a succession of styles or colors in order to distinguish them. But now we will learn the details of how to take charge of our line styles, colors, and point styles. The printed version of this book will not let you see the full effect of manipulating color, but the electronically available versions of the graphs contain all the color and transparency information resulting from the recipes.

In addition to colors and styles, this chapter discusses setting the size of your plot, and introduces three new features of gnuplot 4.4: transparency, new semantics for graph positioning, and plotting with objects.