How to draw legend lines in caption/text without including original plot's TikZ picture?

Question

I would like to reference some plot lines in text/captions. It is possible by defining a label for the plot in the corresponding axis environment. However, I'm using externalization and only want to distribute the PDF files (not the tikzpicture files), but still want to reference plot lines in the text. How to separately add labels for the plot line without having to include the whole tikzpicture?

As a workaround, I include dummy plots and label them, but it results in appearing a dot in the document. Any way to make this tikzpicture hidden and taking zero space would also be useful.

\documentclass{article}
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}
This is how I reference to \ref{hwplot1} and \ref{hwplot2}. But the following 'tikzpicture' results in ploting a dot


%%% This is neccessary for drawing plot lines in the text
\begin{tikzpicture}
    \begin{axis}[hide axis]
        \addplot [
        color=red,
        solid,
        line width=0.9pt,
        forget plot
        ]
        (0,0);\label{hwplot1}
        \addplot [
        color=black,
        dashed,
        line width=1.2pt,
        forget plot
        ]
        (0,0);\label{hwplot2}
    \end{axis}
\end{tikzpicture}%
\end{document}

It might be easier to create you own legend from scratch. It's just a box with tome lines and labels. — John Kormylo, Dec 06 '13 at 13:52
Possibly related: http://tex.stackexchange.com/questions/54794/using-a-pgfplots-style-legend-in-a-plain-old-tikzpicture/54834#54834 — Christian Feuersänger, Dec 07 '13 at 08:49
Exactly what do you mean by referencing plot lines in the text? If you want to illustrate a particular line you can always use something like \tikz{\draw[red] (0,0) -- (5mm,0);} or define a macro if you plan to do it a lot. — John Kormylo, Dec 07 '13 at 14:08

John Kormylo · Answer 1 · 2020-03-10T13:39:17.363

6

\documentclass{article}
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}

\newcommand{\hwplotA}{\raisebox{2pt}{\tikz{\draw[red,solid,line width=0.9pt](0,0) -- (5mm,0);}}}
\newcommand{\hwplotB}{\raisebox{2pt}{\tikz{\draw[black,dashed,line width=1.2pt](0,0) -- (5mm,0);}}}

This is how I reference to {\hwplotA} and {\hwplotB}. 

\end{document}

inserted lines

When in doubt, use a savebox.

\documentclass{article}
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}

\newcommand{\hwplotA}{\raisebox{2pt}{\tikz{\draw[red,solid,line width=0.9pt](0,0) -- (5mm,0);}}}
\newcommand{\hwplotB}{\raisebox{2pt}{\tikz{\draw[black,dashed,line width=1.2pt](0,0) -- (5mm,0);}}}

\begin{figure}[hp]
\sbox0{\hwplotA}\sbox1{\hwplotB}%
\caption{This is how I reference to \usebox0 and \usebox1.}
\end{figure}

\end{document}

edited Mar 10 '20 at 13:39

answered Dec 06 '13 at 23:41

John Kormylo

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Thank you for the answer. I would like to have a inline reference to plot lines as what the MWE does. but without having to include the tikzpicture or at least make it invisible. – M.Reza Dec 07 '13 at 07:51
I replaced the original answer with something more appropriate. BTW, you can't label macros with numbers, so I used letters. – John Kormylo Dec 07 '13 at 14:36
1

This doesn't work in a caption. – Tropilio Mar 10 '20 at 12:25
@Tropilio - Interesting! I wonder if this is new or has always been a problem? – John Kormylo Mar 10 '20 at 13:41
@JohnKormylo I don't know, but I discovered that changing \newcommand to \DeclareRobustCommand solves the problem. – Tropilio Mar 10 '20 at 15:24
@Tropilio: \DeclareRobustCommand seems to solve the problem – honeybadger Jan 04 '21 at 04:53

score 5 · Answer 2 · answered Jan 06 '14 at 15:53

This doesn't eliminate the tikz picture, but it scales it to zero size. Here, it is placed in the middle of the last word "nothing".

\documentclass{article}
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}
This is how I reference to \ref{hwplot1} and \ref{hwplot2}. But the following
  'tikzpicture' results in plotting no%
%%% This is neccessary for drawing plot lines in the text
\scalebox{0}{%
\begin{tikzpicture}
    \begin{axis}[hide axis]
        \addplot [
        color=red,
        solid,
        line width=0.9pt,
        forget plot
        ]
        (0,0);\label{hwplot1}
        \addplot [
        color=black,
        dashed,
        line width=1.2pt,
        forget plot
        ]
        (0,0);\label{hwplot2}
    \end{axis}
\end{tikzpicture}%
}%
thing
\end{document}

enter image description here

indeed not, unless some measures are taken: "a \ref inside of an externalized graphics works only if you issue the required system call manually or by make." — Alessandro Cuttin, Feb 15 '18 at 15:29

score 2 · Answer 3 · answered Jan 09 '15 at 23:04

For my and others future reference, I have taken the excellent example by @steven-b-segletes and generalised it for the automated creation of labels from a cycle list. This is great for reusing labels where you have the legend in a caption, or are using the animate package and dont want 300 repeated references

\documentclass{article}
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}
\newcommand*{\graphlinewidth}{1}
\pgfplotscreateplotcyclelist{mylistNoMarkDarkColour}{%
  {red!80!black,    solid,      line width=\graphlinewidth, mark=none},
  {green!80!black,  solid,      line width=\graphlinewidth, mark=none},
  {blue,    solid,          line width=\graphlinewidth, mark=none},
  {purple,  solid,          line width=\graphlinewidth, mark=none},
  {orange,  solid,          line width=\graphlinewidth, mark=none},
}

% Generate the label references for legends in captions from the given cyle list and reference.
% Also avoids issues with TiKz externalize
% 1: Cycle list name, 2: Reference prefix, 3: Number to produce
\newcommand{\pgfplotsReferenceGenerator}[3]{%
\scalebox{0}{%
\begin{tikzpicture}
\begin{axis}[hide axis, cycle list name = #1]
  \foreach \i   [evaluate=\i] in {1,...,#2}{
    \addplot (0,0); \label{#3\i}
  }
\end{axis}
\end{tikzpicture}%
}%
}

\begin{document}

\pgfplotsReferenceGenerator{mylistNoMarkDarkColour}{5}{dark}
This is great for reusing labels where you have the legend in a caption,
or are using the animate package and dont want 300 repeated references (i.e one \ref{dark1} per frame)
like \ref{dark2} and \ref{dark3} with \ref{dark4} finally \ref{dark5}

\end{document}

What I have not been able to do and would appreciate feedback on:

Automatically detect the length of the cycle list
Correctly disable TiKz externalisation for the graph (I couldn't make it work...)

How to draw legend lines in caption/text without including original plot's TikZ picture?

3 Answers3

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