[Tex/LaTex] How to add some latex eq or symbol in gnuplot

Question

Gnuplot is power for plotting graph in scientific progress.

I have met this problem. I want to add some commands like "$\ddot{x}$".

or $\tau$ on the legend.

I see some people suggest that

plot [-5:5] [-1.5:1.5] sin(x+pi) title "$\\sin(x+\\pi)$"

But it seems it does not work.

Answer 1

To get LaTeX in labels or legends in Gnuplot, you need to use one of the terminals that produce LaTeX code.

For example, you could use the latex terminal:

set terminal latex
set out 'plot.tex'
plot [-5:5] [-1.5:1.5] sin(x+pi) title "$\\sin(x+\\pi)$"
set out

That will produce a plot.tex file that includes the plot using basic TeX statements. You can include that file in your main document using \input{plot.tex}:

\documentclass{article}
\begin{document}
\input{plot.tex}
\end{document}

Which will give you

(notice that the quality isn't overwhelming when using the latex terminal).

You can also use the epslatex terminal:

set terminal epslatex color
set out 'plot.tex'
plot [-5:5] [-1.5:1.5] sin(x+pi) title "$\\sin(x+\\pi)$"
set out

This will include a plot.tex file with all the labels, and a separate plot.eps file including the graphical elements. You can include the output using

\documentclass{article}
\usepackage{graphicx}
\begin{document}
\input{plot.tex}
\end{document}

---

Alternatively, you could create the plots directly within LaTeX, using a package like PGFPlots or pst-plot:

\documentclass{article}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
    enlarge x limits=false,
    legend entries=$\sin{x+\pi}$
]
\addplot [domain=-1.5*pi:1.5*pi, smooth] {sin(deg(x+pi))};
\end{axis} 
\end{tikzpicture}
\end{document}