Pgfplots legend style marker size

Question

I have the following plot:

\begin{tikzpicture}

  \begin{axis}[
  xlabel={\tiny X},
  ylabel={\tiny Y},
  xmin=0, xmax=5,
  ymin=0, ymax=18,
  minor x tick num=4,
  minor y tick num=4,
  ytick={0, 2, 4, 6, 8, 10, 12, 14, 16, 18},
  y tick label style={
      /pgf/number format/.cd,
          fixed,
          fixed zerofill,
          precision=2,
      /tikz/.cd,
      font=\tiny},
  x tick label style={font=\tiny},
  every x tick/.style={color=black, thin},
  every y tick/.style={color=black, thin},
  xtick pos=left,
  ytick pos=left,
  axis on top,
  width=5cm,
  height=5cm,
  legend style={mark options={scale=5.0}, at={(0.97,0.03)}, anchor=south east},
  clip mode=individual
  ]
  \addplot+[
  color=red,
  solid,
  line width=1.0pt,
  mark size=1.8pt,
  mark=star,
  mark options={solid, line width=0.5pt},
  error bars/.cd, y dir=both,y explicit]
  plot coordinates {
  (0, 1)
  (1, 2)
  (2, 4)
  (3, 8)
  (4, 16)
  };
  \addlegendentry{My plot};
  \end{axis}
  \end{tikzpicture}

And I am trying to change the scale/size of the markers inside the legend. I have been looking around for a while now and could not find a solution. The only solution I found was a thread where someone wanted to reduce the scale of the markers in the legend and the suggested solution was to add

    legend style={mark options={scale=0.5}

I tried to use that to increase the scale, but it still doesn't do anything to my final output. I also did try:

    legend style={mark options={size=5pt}

and

    legend style={mark size=5pt}

without success.

I am running: Package: tikz 2010/10/13 v2.10 (rcs-revision 1.76) Package: pgfplots 2015/01/31 v1.12 Data Visualization (1.12)

Does anyone have a suggestion why it would not work, or any other solution to increase the mark size in the legend?

Answer 1

You can use legend image post style={scale=0.5},. For details, consult page 261 of pgfplots manual (version 1.17).

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

  \begin{axis}[
  xlabel={\tiny X},
  ylabel={\tiny Y},
  xmin=0, xmax=5,
  ymin=0, ymax=18,
  minor x tick num=4,
  minor y tick num=4,
  ytick={0, 2, 4, 6, 8, 10, 12, 14, 16, 18},
  y tick label style={
      /pgf/number format/.cd,
          fixed,
          fixed zerofill,
          precision=2,
      /tikz/.cd,
      font=\tiny},
  x tick label style={font=\tiny},
  every x tick/.style={color=black, thin},
  every y tick/.style={color=black, thin},
  xtick pos=left,
  ytick pos=left,
  axis on top,
  width=5cm,
  height=5cm,
  legend image post style={scale=0.5},  %%% <--- here
  legend style={at={(0.97,0.03)}, anchor=south east},
  clip mode=individual
  ]
  \addplot+[
  color=red,
  solid,
  line width=1.0pt,
  mark=star,  
  mark options={mark size=4pt,solid, line width=0.5pt}, %% make size 4pt for demo
  error bars/.cd, y dir=both,y explicit]
  plot coordinates {
  (0, 1)
  (1, 2)
  (2, 4)
  (3, 8)
  (4, 16)
  };
  \addlegendentry{My plot};
  \end{axis}
  \end{tikzpicture}
\end{document}

Another option is to use forget plot in the \addplot+ options and the add

\addlegendimage{red,line width=1.0pt,,mark=star,mark options={mark size=2pt,solid, line width=0.5pt}};
  \addlegendentry{My plot};