pgfplots: Use strings as barchart labels from .csv

Question

I'm trying to plot a vertical bar chart using pfgplots that has strings as labels for the bar charts. (This question has been asked before, but I'm hoping there is a cleaner way to do this now. Perhaps a different package?) Previous Question: pgfplots using strings *from data table* as x axis labels in bar chart

This is what my attempt looked like (MWE):

\documentclass[11pt]{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.9}

\begin{document}
\begin{tikzpicture}
\begin{axis}[xlabel=x axis label,ylabel=y axis label]
\addplot [ybar] table [symbolic x coords=Month, y=Dozers, col sep=comma] {cnrldata.csv};
\end{axis}
\end{tikzpicture} \\
\end{document}

From this I of course get the error:

Package PGF Math Error: Could not parse input 'January' as a floating point number, sorry. The unreadable part was near 'January'.. ... y=Dozers, col sep=comma] {data.csv};

The data in the table looks like this:

Month, Dozers,
January, 0.85,
February, 0.7,

Hopefully there is a better solution to this now, but if not, I will delete this question since it is a duplicate.

Answer 1

It seems that you can do this using xtick labels and \xcoordindex. You first need to read the data into an "array", called \datatable below, using \pgfplotstableread. After this you just tell pgf to access the data in \datatable. This way you can produce

using the code:

\documentclass[11pt]{article}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
\pgfplotsset{compat=1.9}

\usepackage{filecontents}% write data file to make make MWE self contained 
\begin{filecontents}{dozers.csv}
Month, Dozers,
Jan, 0.85,
Feb, 0.7,
Mar, 0.6,
Apr, 0.75,
May, 0.8,
June, 0.9,
\end{filecontents}

\begin{document}

\pgfplotstableread[col sep=comma,]{dozers.csv}\datatable
\begin{tikzpicture}
\begin{axis}[
    ybar,
    xlabel={Month},
    xtick=data,
    xticklabels from table={\datatable}{Month},
    ylabel={Dozers}]
    \addplot table [x expr=\coordindex, y={Dozers}]{\datatable};
\end{axis}
\end{tikzpicture} \\
\end{document}

EDIT

Following the solution to Using Labels from a File in PGFplot it seems that you don't have to read the file in first using \pgfplotstableread:

\documentclass[11pt]{article}
\usepackage{pgfplots}
%\usepackage{pgfplotstable}
\pgfplotsset{compat=1.9}

\usepackage{filecontents}
\begin{filecontents}{dozers.csv}
Month Dozers
Jan 0.85
Feb 0.7
Mar 0.6
Apr 0.75
May 0.8
June 0.9
\end{filecontents}

\begin{document}

%\pgfplotstableread[col sep=comma,]{dozers.csv}\datatable
\begin{tikzpicture}
\begin{axis}[
    ybar, ymin=0, ylabel=Dozers,
    xlabel=Month,
    xtick=data,
    xticklabels from table={dozers.csv}{Month},
    ]
    \addplot table [x expr=\coordindex, y=Dozers]{dozers.csv};
\end{axis}
\end{tikzpicture} \\
\end{document}

To get this to work I had to remove the commas from the data file. The output is essentially the same as above except that I added ymin-0.