Plotting grouped bar chart with 2 sets of y-axes in pgfplot

I'm trying to plot a bar chart with pgfplots, with two data series, and two separate y-axes (one on the left, one on the right).

In order to have different axes, it seems that I need to put each \addplot in its own axis environment (see code below). However, when I do this, the bars are drawn on top of each other and I can't separate them:

If the \addplot commands are in the same axis, the bars are grouped correctly, but then I can't use a second y-axis.

This question seemed promising, but all the plots there are drawn in the first axis environment

Here's my code:

\documentclass{minimal}
\usepackage[utf8]{inputenc}
\usepackage{pgfplots}
\pgfplotsset{width=9cm,compat=1.5.1}

\begin{document}

\begin{tikzpicture}
\begin{axis}[
ybar,
symbolic x coords={(a), (b), (c), (d), (e), (f), (g), (h), (i)},
axis y line*=left,
axis x line=none,
ymin=0, ymax=6,
ylabel=data set 1,
enlarge x limits=0.2,
xtick=data]
\addplot[mark=*,draw=black,fill=cyan,error bars/.cd, y dir=both, y explicit, error bar style={line width=1pt,solid, black}] coordinates {
((a),2.208) +- (0.004, 0.004)
((b),2.394) +- (0.028, 0.028)
((c), 2.452) +- (0.040, 0.040)
((d), 4.000) +- (0.757, 0.757)
((e), 2.561) +- (0.245, 0.245)
((f), 2.600) +- (0.423, 0.423)
((g), 2.731) +- (0.267, 0.267)
((h), 2.840) +- (0.207, 0.207)
((i), 2.000) +- (0.146, 0.146)
};
\end{axis} % start a new axis for the second data set
\begin{axis}[
ybar,
symbolic x coords={(a), (b), (c), (d), (e), (f), (g), (h), (i)},
axis y line*=right,
ymin=0, ymax=5,
ylabel=data set 2,
enlarge x limits=0.2]
\addplot[mark=*,fill=red!50,error bars/.cd, y dir=both, y explicit, error bar style={line width=1pt,solid, black}] coordinates {
((a),2.21) +- (0.004, 0.004)
((b),1.394) +- (0.028, 0.028)
((c), 3.452) +- (0.040, 0.040)
((d), 2.346) +- (0.757, 0.757)
((e), 1.561) +- (0.245, 0.245)
((f), 1.3300) +- (0.423, 0.423)
((g), 1.931) +- (0.267, 0.267)
((h), 2.820) +- (0.207, 0.207)
((i), 3.00) +- (0.146, 0.146)
};
\end{axis}
\end{tikzpicture}

\end{document}

• Welcome to TeX-SE! Could you please describe more clearly what your target output is? And as for "In order to have different axes, it seems that I need to put each \addplot in its own axis environment (see code below)": no, you can have just an empty axis with some appropriate xmin, xmax, ymin and ymax. – user121799 Mar 11 '19 at 18:33
• @marmot My target output is like the chart in the image, but with the 2 bars for each category next to each other, not drawn on top of each other. Regarding the empty axis environment: I understand that I can do that and it'll draw the second axis, but I want the second set of data to be plotted according to that axis. – Joe Malt Mar 11 '19 at 20:15

Perhaps you figured this out, or time has passed so you don't need it, but anyways: With the appropriate bar width and bar shift, as well as a corresponding xshift for the markers, you can get this:

\documentclass{article} % don't use minimal
\usepackage[utf8]{inputenc}
\usepackage{pgfplots}
\pgfplotsset{width=9cm,compat=1.5.1}

\begin{document}

\begin{tikzpicture}[
declare function={
barW=8pt; % width of bars
barShift=barW/2; % bar shift
}
]
\begin{axis}[
ybar,
symbolic x coords={(a), (b), (c), (d), (e), (f), (g), (h), (i)},
axis y line*=left,
axis x line=none,
ymin=0, ymax=6,
ylabel=data set 1,
enlarge x limits=0.1,
xtick=data
]
draw=black,
fill=cyan,
error bars/.cd,
y dir=both,
y explicit,
error bar style={line width=1pt,solid, black}
] coordinates {
((a),2.208) +- (0.004, 0.004)
((b),2.394) +- (0.028, 0.028)
((c), 2.452) +- (0.040, 0.040)
((d), 4.000) +- (0.757, 0.757)
((e), 2.561) +- (0.245, 0.245)
((f), 2.600) +- (0.423, 0.423)
((g), 2.731) +- (0.267, 0.267)
((h), 2.840) +- (0.207, 0.207)
((i), 2.000) +- (0.146, 0.146)
};
\end{axis} % start a new axis for the second data set
\begin{axis}[
ybar,
bar width=barW,
bar shift=barShift,
symbolic x coords={(a), (b), (c), (d), (e), (f), (g), (h), (i)},
axis y line*=right,
ymin=0, ymax=5,
ylabel=data set 2,
enlarge x limits=0.1
]
fill=red!50,
error bars/.cd,
y dir=both,
y explicit,
error bar style={line width=1pt,solid, black}
] coordinates {
((a),2.21) +- (0.004, 0.004)
((b),1.394) +- (0.028, 0.028)
((c), 3.452) +- (0.040, 0.040)
((d), 2.346) +- (0.757, 0.757)
((e), 1.561) +- (0.245, 0.245)
((f), 1.3300) +- (0.423, 0.423)
((g), 1.931) +- (0.267, 0.267)
((h), 2.820) +- (0.207, 0.207)
((i), 3.00) +- (0.146, 0.146)
};
\end{axis}
\end{tikzpicture}

\end{document}