grouped bar chart with pgfplots

Question

I am trying to create a grouped bar chart with pgfplots, like this one:

but I can't put the values over the bars, like this one:

My code is:

\documentclass{article}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
\pgfplotsset{compat=newest}
\usepackage{caption}
\usepackage{polyglossia}
\setdefaultlanguage{portuges}

\begin{document}

\begin{figure}[h]
\makeatletter
\pgfplotsset{
    calculate offset/.code={
        \pgfkeys{/pgf/fpu=true,/pgf/fpu/output format=fixed}
        \pgfmathsetmacro\testmacro{(\pgfplotspointmeta *10^\pgfplots@data@scale@trafo@EXPONENT@y)*\pgfplots@y@veclength)}
        \pgfkeys{/pgf/fpu=false}
    },
    every node near coord/.style={
        /pgfplots/calculate offset,
        yshift=-\testmacro
    }
}
%0 - aramente   1 - Às vezes   2 - Quase sempre   4 - Sempre
\pgfplotstableread{
  %2013-2014    %2012-2013  %2011-2012
0 32        35      20
1 28        45      23
2 30        24      25
3 10        68      70
}\dataset
\begin{tikzpicture}
\begin{axis}[ybar,
        width=12cm,
        height=8cm,
        ymin=0,
        ymax=100,        
        ylabel={Percentagem},
        xtick=data,
        xticklabels = {
            Raramente,
            Às vezes,
            Quase sempre,
            Sempre
            %Category 5,
            %Category 6
        },
        xticklabel style={yshift=-10ex},
        major x tick style = {opacity=0},
        minor x tick num = 1,
        minor tick length=2ex,
        every node near coord/.append style={
                anchor=east,
                rotate=90
        }
        ]
\addplot[draw=black,fill=blue!20, nodes near coords=2013-2014] table[x index=0,y index=1] \dataset; %ano de 2013-2014
\addplot[draw=black,fill=blue!40, nodes near coords=2012-2013] table[x index=0,y index=2] \dataset; %ano de 2012-2013
\addplot[draw=black,fill=blue!60, nodes near coords=2011-2012] table[x index=0,y index=3] \dataset; %ano de 2011-2012
\end{axis}
\end{tikzpicture}
\captionsetup{justification=centerlast, margin=10ex, labelfont=bf, textfont=it, format=plain, labelformat=default, labelsep=endash, font=small, name=Gráfico\,}
\caption{Em sua casa é costume desligar os equipamentos no controlo remoto, deixando-os em standby (modo de “espera”)?}\label{Questao01}

\end{figure}

\end{document}

Answer 1

nodes near coords alone, without any further customization, results in the desired nodes on top of the bars.

This has the disadvantage that your legend description are no longer a standard nodes near coords instruction. The way that pgfplots handles such a case would be to use legend entries, perhaps as in the following example:

\documentclass{article}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
\pgfplotsset{compat=newest}
\usepackage{caption}

\begin{document}
\thispagestyle{empty}

\begin{figure}[h]
%0 - aramente   1 - Às vezes   2 - Quase sempre   4 - Sempre
\pgfplotstableread{
  %2013-2014    %2012-2013  %2011-2012
0 32        35      20
1 28        45      23
2 30        24      25
3 10        68      70
}\dataset
\begin{tikzpicture}
\begin{axis}[ybar,
        width=12cm,
        height=8cm,
        ymin=0,
        ymax=100,        
        ylabel={Percentagem},
        xtick=data,
        xticklabels = {
            \strut Raramente,
            \strut Às vezes,
            \strut Quase sempre,
            \strut Sempre
            %Category 5,
            %Category 6
        },
        %xticklabel style={yshift=-10ex},
        major x tick style = {opacity=0},
        minor x tick num = 1,
        minor tick length=2ex,
        every node near coord/.append style={
                anchor=west,
                rotate=90
        },
        legend entries={2013-2014 ,2012-2013 ,2011-2012 },
        legend columns=3,
        legend style={draw=none,nodes={inner sep=3pt}},
        ]
\addplot[draw=black,fill=blue!20, nodes near coords] table[x index=0,y index=1] \dataset; %ano de 2013-2014
\addplot[draw=black,fill=blue!40, nodes near coords] table[x index=0,y index=2] \dataset; %ano de 2012-2013
\addplot[draw=black,fill=blue!60, nodes near coords] table[x index=0,y index=3] \dataset; %ano de 2011-2012
\end{axis}
\end{tikzpicture}
\captionsetup{justification=centerlast, margin=10ex, labelfont=bf, textfont=it, format=plain, labelformat=default, labelsep=endash, font=small, name=Gráfico\,}
\caption{Em sua casa é costume desligar os equipamentos no controlo remoto, deixando-os em standby (modo de “espera”)?}\label{Questao01}

\end{figure}

\end{document}

Here, nodes near coords draws the individual bar values. The legend entries, together with a bit of legend customization, results in the description on top of the plot.

Note that \strut in the tick labels causes all tick labels to have the same size (even below the text's base line), such that they are aligned vertically (thanks @egreg for the suggestion).