#### Overview of this book

gnuplot is the world's finest technical plotting software, used by scientists, engineers, and others for many years. It is in constant development and runs on practically every operating system, and can produce output in almost any format. The quality of its 3d plots is unmatched and its ability to be incorporated into computer programs and document preparation systems is excellent. gnuplot Cookbook ñ it will help you master gnuplot. Start using gnuplot immediately to solve your problems in data analysis and presentation. Quickly find a visual example of the graph you want to make and see a complete, working script for producing it. Learn how to use the new features in gnuplot 4.4. Find clearly explained, working examples of using gnuplot with LaTeX and with your own computer programming language. You will master all the ins and outs of gnuplot through gnuplot Cookbook. You will learn to plot basic 2d to complex 3d plots, annotate from simple labels to equations, integrate from simple scripts to full documents and computer progams. You will be taught to annotate graphs with equations and symbols that match the style of the rest of your text, thus creating a seamless, professional document. You will be guided to create a web page with an interactive graph, and add graphical output to your simulation or numerical analysis program. Start using all of gnuplot's simple to complex features to suit your needs, without studying its 200 page manual through this Cookbook.
gnuplot Cookbook
Credits
www.PacktPub.com
Preface
Free Chapter
Plotting Curves, Boxes, Points, and more
Annotating with Labels and Legends
Applying Colors and Styles
Combining Multiple Plots
Programming gnuplot and Dealing with Data
The Third Dimension
Using and Making Graphical User Interfaces
Surveying Special Topics
Finding Help and Information
Index

## Putting arrows on the axes

The following style is popular in the classroom:

Notice that there is no border, but rather one pair of axes sporting arrows.

### How to do it…

Execute the following script and you should see something very similar to the previous figure:

```set arrow from graph 0,1 to graph 0,1.1 filled
set arrow from graph 1,0 to graph 1.1,0 filled
set tmargin 5
set rmargin 20
set border 3
set tics nomirror
set grid
plot sin(x)/x lw 2```

### How it works…

We learned about arrows in Chapter 2, Annotating with Labels and Legends. The first two lines define two arrows positioned using the `graph` coordinate system. This coordinate system is ideal for our purposes here, because `1` in this system is defined to be the very edge of the graph, which is exactly where we want the arrows to start. We also set them to be `filled`; as we saw in Chapter 2, Annotating with Labels and Legends, we can also, if we want, get very specific as to precisely how our little arrowheads are drawn. The `set border 3` command tells...