24

The legend entries created by a more complex math formula as in this example are overlapping and the alignment to the lines is wrong.

\documentclass[]{scrbook}

\usepackage{pgfplots}
\usepackage{amsmath}

\begin{document}
\pgfplotsset{width=0.8\textwidth, height=0.6\textwidth}
\centering
\begin{tikzpicture}
\begin{axis}[scale only axis,samples=2000,
         /pgfplots/enlargelimits=false,
         legend style={legend pos=north west}]
  \addplot[domain=0:30] gnuplot{5*exp(-((x-5*pi)/(2.5*pi))**2)*sin(2*x)+x};
  \addplot[domain=0:30] gnuplot{x};
  \legend{$f(x) = 5\exp\left(-\left(\dfrac{x-5\pi}{2.5\pi}\right)^2\right)
             \sin(2x) + x$,
          $f(x)_\text{fit} = x$}
\end{axis}
\end{tikzpicture}
\end{document}

enter image description here

Matthias Pospiech
  • 11,681
  • 1
    Or you can shift the formula slightly with \legend{{\raisebox{1.5ex}{$f(x) = 5\exp\left(-\left(\dfrac{x-5\pi}{2.5\pi}\right)^2\right)\sin(2x) + x$}},$f(x)_\text{fit} = x$} – percusse Mar 19 '12 at 19:46

1 Answers1

48

The alignment can be changed using

legend cell align=left,

The other issues can be changed in a variety of different ways- in what follows I didn't use samples=2000 as it increases the compiling time quite significantly- the question was independent from this though.

  • using legend style={legend pos=north west,font=\tiny} gives

enter image description here

\begin{tikzpicture}
\begin{axis}[scale only axis,
                    legend cell align=left,
         /pgfplots/enlargelimits=false,
          legend style={legend pos=north west,font=\tiny}]
  \addplot[domain=0:30] {5*exp(-((x-5*pi)/(2.5*pi))^2)*sin(deg(2*x))+x};
  \addplot[domain=0:30] {x};
  \legend{$f(x) = 5\exp\left(-\left(\dfrac{x-5\pi}{2.5\pi}\right)^2\right)
             \sin(2x) + x$,
          $f(x)_\text{fit} = x$}
\end{axis}
\end{tikzpicture}

  • Using @percusse's \raisebox idea (permission to post given during chat- thanks @percusse!)

    \legend{\raisebox{2.5ex}{$f(x) = 5\exp\left(-\left(\dfrac{x-5\pi}{2.5   \pi}\right)^2\right)\sin(2x) + x$}

enter image description here

  • Using a blank line in the legend

enter image description here

\begin{tikzpicture}
\begin{axis}[scale only axis,
         /pgfplots/enlargelimits=false,
         legend cell align=left,
         legend style={legend pos=north west,font=\tiny}]
  \addplot[domain=0:30] {5*exp(-((x-5*pi)/(2.5*pi))^2)*sin(deg(2*x))+x};
  \addlegendentry{$f(x) = 5\exp\left(-\left(\dfrac{x-5\pi}{2.5\pi}\right)^2\right)$}
  \addlegendimage{empty legend};
  \addlegendentry{};
  \addplot[domain=0:30] {x};
  \addlegendentry{$f(x)_\text{fit} = x$};
\end{axis}
\end{tikzpicture}
  • Or you could put the legend in the caption using \label and \ref

enter image description here

\begin{figure}
\begin{tikzpicture}
\begin{axis}[scale only axis,
                    legend cell align=left,
         /pgfplots/enlargelimits=false,
          legend style={legend pos=north west,font=\tiny}]
  \addplot[domain=0:30] {5*exp(-((x-5*pi)/(2.5*pi))^2)*sin(deg(2*x))+x};
  \label{plot:firstplot};
  \addplot[domain=0:30] {x};
  \label{plot:secondplot};
\end{axis}
\end{tikzpicture}
\caption{\ref{plot:firstplot} is $f(x) = 5\exp\left(-\left(\dfrac{x-5\pi}{2.5\pi}\right)^2\right)\sin(2x) + x$ and 
\ref{plot:secondplot} is $f(x)_\text{fit}=x$}
\end{figure}
cmhughes
  • 100,947