5

I have some data stored to file, that I would like to plot with pgfplots. The data is stored row-wise, that is the file looks something like this:

a  1 2 3 4 5
b  6 7 8 9 0
c  2 4 6 8 0
...

Pgfplots expects the data to be column-wise, however. To solve this, I transpose the table using \pgfplotstabletranspose. This seems to have problems with the row titles, however.

The following minimal example shows what I have accomplished so far.

\documentclass{article}

\usepackage{pgfplots}
\usepackage{pgfplotstable}

\begin{document}

  \begin{tikzpicture}
    \begin{axis}
      \pgfplotstableread{
        x  1  2  3  4  5
        y  1  4  9 16 25
      }\datatable;
      \pgfplotstabletranspose\datatable{\datatable};

      \addplot table {\datatable};
    \end{axis}
  \end{tikzpicture}

\end{document}

The desired output is the following plot:

enter image description here

Unfortunately, I get the following error:

Package PGF Math Error: Could not parse input 'x' as a floating point number, sorry.

(Interestingly, when using -interaction=nonstopmode the plot is generated as desired nonetheless, but the error is annoying...)

Can I somehow tell pgfplots, that the first column contains the row titles to get rid of the error messages?

luator
  • 189

1 Answers1

3

It's necessary to train \pgfplotstabletranspose to maintain the column names.

Add a dummy row to the data, having the values colnames 0 1 2 3 4 (whereas colnames could be replaced by anything basically). Call the 

\addplot table[x=xrow,y=yrow] {\otherdatatable};

(I've used another macro for the transposed table. I am not sure if using the same macro won't would be healthy)

\documentclass{article}

\usepackage{pgfplots}
\usepackage{pgfplotstable}

\pgfplotsset{compat=1.12}
\begin{document}

  \begin{tikzpicture}
    \begin{axis}
      \pgfplotstableread{%
          colnames    0  1  2  3  4
          xrow        1  2  3  4  5
          yrow        1  4  9 16 25
      }\datatable;
      \pgfplotstabletranspose[colnames from=colnames]\otherdatatable{\datatable};

 \addplot table[x=xrow,y=yrow] {\otherdatatable};
    \end{axis}
  \end{tikzpicture}

\end{document}

I used xrow and yrow to prevent a possible confusion (x=x,y=y), since I don't know the internals of \pgfplotstable etc.

enter image description here