3

I have two figures that I'd like to connect; both are generated with pgfplots (and in this example, gnuplot). The following works exactly as expected:

\documentclass{beamer}
\usepackage{graphicx}
\usepackage{pgfplots}
\pgfplotsset{compat=1.7}
\begin{document}
\begin{frame}
  \tikzstyle{every picture}+=[remember picture]
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm, enlargelimits = false]
        \addplot gnuplot[id=1, domain=0:1] {exp(x)};
        \coordinate (upper8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (upper6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (lower8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymin});
        \coordinate (lower6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymin});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm, enlargelimits = false]
        \addplot gnuplot[id=2, domain=.6:.8] {exp(x)};
        \coordinate (no) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (nw) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (so) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymin});
        \coordinate (sw) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymin});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \tikz[overlay] \draw (upper8) -- (no);
  \tikz[overlay] \draw (upper6) -- (nw);
  \tikz[overlay] \draw[dashed] (lower8) -- (so);
  \tikz[overlay] \draw[dashed] (lower6) -- (sw);
\end{frame}
\end{document}
%%% Local Variables:
%%% LaTeX-command: "latex -shell-escape"
%%% End:

LaTeX rendering

As already observed in the answer to another question, ymax does not behave as expected once the (second) plot has a logarithmic axis, though:

\documentclass{beamer}
\usepackage{graphicx}
\usepackage{pgfplots}
\pgfplotsset{compat=1.7}
\begin{document}
\begin{frame}
  \tikzstyle{every picture}+=[remember picture]
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm, enlargelimits = false]
        \addplot gnuplot[id=3, domain=0:1] {exp(x)};
        \coordinate (upper8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (upper6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (lower8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymin});
        \coordinate (lower6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymin});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm, enlargelimits = false, ymode=log]
        \addplot gnuplot[id=4, domain=.6:.8] {exp(x)};
        \coordinate (no) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (nw) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (so) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymin});
        \coordinate (sw) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymin});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \tikz[overlay] \draw (upper8) -- (no);
  \tikz[overlay] \draw (upper6) -- (nw);
  \tikz[overlay] \draw[dashed] (lower8) -- (so);
  \tikz[overlay] \draw[dashed] (lower6) -- (sw);
\end{frame}
\end{document}
%%% Local Variables:
%%% LaTeX-command: "latex -shell-escape"
%%% End:

LaTeX rendering (log case)

So my question is: What should I use with the logarithmic plot if not ymax?

As an aside, when I toyed around with this, I noticed that without the option enlargelimits=false, the connecting lines end up quite far from where they're supposed to go, too; am I doing something wrong? Here's the code:

\documentclass{beamer}
\usepackage{graphicx}
\usepackage{pgfplots}
\pgfplotsset{compat=1.7}
\begin{document}
\begin{frame}
  \tikzstyle{every picture}+=[remember picture]
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm]
        \addplot gnuplot[id=5, domain=0:1] {exp(x)};
        \coordinate (upper8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (upper6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (lower8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymin});
        \coordinate (lower6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymin});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm]
        \addplot gnuplot[id=6, domain=.6:.8] {exp(x)};
        \coordinate (no) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (nw) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (so) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymin});
        \coordinate (sw) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymin});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \tikz[overlay] \draw (upper8) -- (no);
  \tikz[overlay] \draw (upper6) -- (nw);
  \tikz[overlay] \draw[dashed] (lower8) -- (so);
  \tikz[overlay] \draw[dashed] (lower6) -- (sw);
\end{frame}
\end{document}
%%% Local Variables:
%%% LaTeX-command: "latex -shell-escape"
%%% End:

LaTeX rendering (enlargelimits=true case)

Community
  • 1
anonymous
  • 1,159
  • This isn't because axis cs: doesn't work with logarithmic axes (it does). Do you have a particular reason for using separate tikzpictures instead of simply putting both the axes and the drawing commands into one? – Jake Feb 15 '13 at 19:53
  • Indeed; I do not know what made me blame axis cs when the problem is clearly with ymax. – anonymous Feb 15 '13 at 19:57
  • I have three figures; they are inside \only<1-2>, \only<1>, and \only<2> blocks, respectively; that is why I use separate tikzpictures. Maybe the key from http://tex.stackexchange.com/questions/6135/how-to-make-beamer-overlays-with-tikz-node/6155#6155 could be used instead but I expected this to be the easier route. – anonymous Feb 15 '13 at 19:59

1 Answers1

4

The offset of the lines is due to a bug in PGFPlots. You can work around it by setting \pgfplotsset{cell picture=if necessary}:

\documentclass{beamer}
\usepackage{graphicx}
\usepackage{pgfplots}
\pgfplotsset{compat=1.7, cell picture=if necessary}
\begin{document}
\begin{frame}
  \tikzstyle{every picture}+=[remember picture]
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm]
        \addplot gnuplot[id=5, domain=0:1] {exp(x)};
        \coordinate (upper8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (upper6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (lower8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymin});
        \coordinate (lower6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymin});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm]
        \addplot gnuplot[id=6, domain=.6:.8] {exp(x)};
        \coordinate (no) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (nw) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (so) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymin});
        \coordinate (sw) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymin});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \tikz[overlay] \draw (upper8) -- (no);
  \tikz[overlay] \draw (upper6) -- (nw);
  \tikz[overlay] \draw[dashed] (lower8) -- (so);
  \tikz[overlay] \draw[dashed] (lower6) -- (sw);
\end{frame}
\end{document}

For the logarithmic axis, the solution is given at the answer you linked to: Use the intersection coordinate system notation (\coordinate (no) at ({axis cs:0.8,0}|-{rel axis cs:0,1});):

\documentclass{beamer}
\usepackage{graphicx}
\usepackage{pgfplots}
\pgfplotsset{compat=1.7, cell picture=if necessary}
\begin{document}
\begin{frame}
  \tikzstyle{every picture}+=[remember picture]
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm, enlargelimits = false]
        \addplot gnuplot[id=3, domain=0:1] {exp(x)};
        \coordinate (upper8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (upper6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymax});
        \coordinate (lower8) at (axis cs:.8,\pgfkeysvalueof{/pgfplots/ymin});
        \coordinate (lower6) at (axis cs:.6,\pgfkeysvalueof{/pgfplots/ymin});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \begin{figure}
    \centering
    \begin{tikzpicture}
      \begin{axis}[height=4cm, width=10cm, enlargelimits = false, ymode=log]
        \addplot gnuplot[id=4, domain=.6:.8] {exp(x)};
        \coordinate (no) at ({axis cs:0.8,0}|-{rel axis cs:0,1});
        \coordinate (nw) at ({axis cs:0.6,0}|-{rel axis cs:0,1});
        \coordinate (so) at ({axis cs:0.8,0}|-{rel axis cs:0,0});
        \coordinate (sw) at ({axis cs:0.6,0}|-{rel axis cs:0,0});
      \end{axis}
    \end{tikzpicture}
  \end{figure}
  \tikz[overlay] \draw (upper8) -- (no);
  \tikz[overlay] \draw (upper6) -- (nw);
  \tikz[overlay] \draw[dashed] (lower8) -- (so);
  \tikz[overlay] \draw[dashed] (lower6) -- (sw);
\end{frame}
\end{document}
Community
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Jake
  • 232,450