Reading an unusual coordinates file in PGFPlots

Question

I have a pgfplot (which works fine), but I want to automatically load the data from a file: data.dat:

  ( 0 , 0.295027 )
  ( 1 , 0.295027 )
  ( 2 , 0.25965 )
  ( 3 , 0.219873 )
  ( 4 , 0.197843 )
  ( 5 , 0.18409 )
  ( 9582 , 0.0392299 )
  ( 9583 , 0.0392299 )
  ( 9941 , 0.0392299 )
  ( 9942 , 0.0392299 )
  ( 10250 , 0.0392299 )
  ( 10987 , 0.0392299 )
  ( 10988 , 0.0392299 )
  ( 10989 , 0.0392299 )
  ( 10990 , 0.0392299 )
  ( 10991 , 0.0392299 )
  ( 10992 , 0.0392299 )
  ( 10993 , 0.0392299 )
  ( 10994 , 0.0392299 )

I've been searching around and I found posts on how to read in csv file (addplot table [x=a, y=c, col sep=comma] {data.csv};), but I can't figure out how to do it with this format (a,b):

\documentclass[varwidth]{standalone}[2011/12/21]
\usepackage{pgfplots}
\pgfplotsset{compat=1.3} 
\usepackage{etex} 
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage{fancybox}
\usepackage{float}
\usepackage{setspace}

\begin{document}
\begin{tikzpicture}[scale=0.8]
\begin{axis}[
axis x line=bottom,
axis y line=left,
xlabel=Number of moves,
xmode=log,log basis x=10,
xmax = 500,
ymin = 1.3]
\addplot[dotted] coordinates {
 (1,1.7)
 (500,1.7)
 };
\addplot[solid, gray] coordinates {
 ( 0 , 3.9259 )
 ( 1 , 3.9259 )
 ( 2 , 3.52535 )
 ( 10994 , 1.62303 )
};
\end{axis}
\begin{axis}[
axis x line=bottom,
axis y line=right,
xmax = 500,
ymin = 0.01,
% ymax = 0.25,
xmode=log,log basis x=10,
% xlabel=Number of moves,
%legend columns=1,
%legend entries={$f^a(s)$;, $f(s)$;, $f(s_\text{best})$},
%legend to name=named,
ylabel=DI]
% legend pos= north west]
\addplot[dashed] coordinates {
  ( 0 , 0.295027 )
  ( 1 , 0.295027 )
  ( 2 , 0.25965 )
  ( 3 , 0.219873 )
  ( 4 , 0.197843 )
  ( 5 , 0.18409 )
  ( 9582 , 0.0392299 )
  ( 9583 , 0.0392299 )
  ( 9941 , 0.0392299 )
  ( 9942 , 0.0392299 )
  ( 10250 , 0.0392299 )
  ( 10987 , 0.0392299 )
  ( 10988 , 0.0392299 )
  ( 10989 , 0.0392299 )
  ( 10990 , 0.0392299 )
  ( 10991 , 0.0392299 )
  ( 10992 , 0.0392299 )
  ( 10993 , 0.0392299 )
  ( 10994 , 0.0392299 )
};
\end{axis}
\end{tikzpicture}
\end{document}

Answer 1

You can keep the input file format and tell pgfplots to silently ignore the parenthesis characters.

This works using the ignore chars key:

\documentclass{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.12} 

\begin{document}
\begin{tikzpicture}
\begin{axis}[
axis x line=bottom,
axis y line=right,
xmode=log,log basis x=10,
ylabel=DI]
\addplot[dashed] table[ignore chars={(,)},col sep=comma] {data.dat};
\end{axis}
\end{tikzpicture}
\end{document}

with file

  ( 0 , 0.295027 )
  ( 1 , 0.295027 )
  ( 2 , 0.25965 )
  ( 3 , 0.219873 )
  ( 4 , 0.197843 )
  ( 5 , 0.18409 )
  ( 9582 , 0.0392299 )
  ( 9583 , 0.0392299 )
  ( 9941 , 0.0392299 )
  ( 9942 , 0.0392299 )
  ( 10250 , 0.0392299 )
  ( 10987 , 0.0392299 )
  ( 10988 , 0.0392299 )
  ( 10989 , 0.0392299 )
  ( 10990 , 0.0392299 )
  ( 10991 , 0.0392299 )
  ( 10992 , 0.0392299 )
  ( 10993 , 0.0392299 )
  ( 10994 , 0.0392299 )

Answer 2

Be cause you have your coordinates formatted as PGFPlots needs them, you can try to include your data file into your \addplot command. With something like this:

Add this command definition into your preamble

\makeatletter
\newcommand*\readcoords[1]{\@@input #1 }
\makeatother

Then just try it into your plot:

\addplot[dashed] coordinates {\readcoords{data.dat}};

This is based on this answer by Martin Scharrer.

Answer 3

After reconsidering and Nicolas' remark, I don't think there is an easy way. So I converted my data to the following:

\documentclass[varwidth]{standalone}[2011/12/21]
\usepackage{pgfplots}
 \pgfplotsset{compat=1.3} 
\usepackage{etex} 
 \usepackage{amsmath}
 \usepackage{graphicx}
 \usepackage{fancybox}
\usepackage{pgfplots}
\usepackage{float}
\usepackage{setspace}

\begin{filecontents}{test.data}
coordinates {
   0    0.295027
   1    0.295027
   2    0.25965
\end{filecontents}

\begin{document}
\begin{tikzpicture}[scale=0.8]
\begin{axis}[
axis x line=bottom,
axis y line=left,
xlabel=Number of moves,
xmode=log,log basis x=10,
xmax = 500,
ymin = 1.3]
\addplot[dotted] file {test.data};
\end{axis}
\end{tikzpicture}
\end{document}