Tikz Stacked Bar Chart with Text

Question

I have the following stacked bar chart and want to put some text behind each bar element and some text into each of the colored areas.

Do you have some ideas, how I could achieve that? The following latex example shows, how the figure can be generated:

\documentclass{article}

\usepackage{xcolor}
\usepackage{tikz}
\usepackage{pgfplots}

\definecolor{findOptimalPartition}{HTML}{D7191C}
\definecolor{storeClusterComponent}{HTML}{FDAE61}
\definecolor{dbscan}{HTML}{ABDDA4}
\definecolor{constructCluster}{HTML}{2B83BA}

\begin{document}
\begin{figure}
\centering
\begin{tikzpicture}
\begin{axis}[
    xbar stacked,
    legend style={
    legend columns=4,
        at={(xticklabel cs:0.5)},
        anchor=north,
        draw=none
    },
    ytick=data,
    axis y line*=none,
    axis x line*=bottom,
    tick label style={font=\footnotesize},
    legend style={font=\footnotesize},
    label style={font=\footnotesize},
    xtick={0,100,200,300,400,500,600},
    width=.9\textwidth,
    bar width=6mm,
    xlabel={Time in ms},
    yticklabels={A, B, C, D, E, F},
    xmin=0,
    xmax=600,
    area legend,
    y=8mm,
    enlarge y limits={abs=0.625},
]
\addplot[findOptimalPartition,fill=findOptimalPartition] coordinates
{(20,0) (108,1) (5,2) (3,3) (108,4) (20,5)};
\addplot[storeClusterComponent,fill=storeClusterComponent] coordinates
{(1.4,0) (2,1) (5,2) (3,3) (2,4) (1,5)};
\addplot[dbscan,fill=dbscan] coordinates
{(288,0) (358,1) (5,2) (3,3) (358,4) (288,5)};
\addplot[constructCluster,fill=constructCluster] coordinates
{(6,0) (54,1) (5,2) (3,3) (54,4) (6,5)};
\legend{S, T, Q, R}
\end{axis}  
\end{tikzpicture}
\caption{X}
\label{fig:stats}
\end{figure}
\end{document}

Answer 1

If you add nodes before \end{axis}, they get written over by the bar plot. If you put it after \end{axis}, scoping resets all scale information to zero. So you have to define the coordinates before and write the text after.

\documentclass{article}

\usepackage{xcolor}
\usepackage{tikz}
\usepackage{pgfplots}

\newlength{\xdim}

\definecolor{findOptimalPartition}{HTML}{D7191C}
\definecolor{storeClusterComponent}{HTML}{FDAE61}
\definecolor{dbscan}{HTML}{ABDDA4}
\definecolor{constructCluster}{HTML}{2B83BA}

\begin{document}
\begin{figure}
\centering
\begin{tikzpicture}
\begin{axis}[
    xbar stacked,
    legend style={
    legend columns=4,
        at={(xticklabel cs:0.5)},
        anchor=north,
        draw=none
    },
    ytick=data,
    axis y line*=none,
    axis x line*=bottom,
    tick label style={font=\footnotesize},
    legend style={font=\footnotesize},
    label style={font=\footnotesize},
    xtick={0,100,200,300,400,500,600},
    width=.9\textwidth,
    bar width=6mm,
    xlabel={Time in ms},
    yticklabels={A, B, C, D, E, F},
    xmin=0,
    xmax=600,
    area legend,
    y=8mm,
    enlarge y limits={abs=0.625},
]
\addplot[findOptimalPartition,fill=findOptimalPartition] coordinates
{(20,0) (108,1) (5,2) (3,3) (108,4) (20,5)};
\addplot[storeClusterComponent,fill=storeClusterComponent] coordinates
{(1.4,0) (2,1) (5,2) (3,3) (2,4) (1,5)};
\addplot[dbscan,fill=dbscan] coordinates
{(288,0) (358,1) (5,2) (3,3) (358,4) (288,5)};
\addplot[constructCluster,fill=constructCluster] coordinates
{(6,0) (54,1) (5,2) (3,3) (54,4) (6,5)};
\legend{S, T, Q, R}
\coordinate (A) at (200,0);% ******** start of changes ************
\coordinate (B) at (300,8mm);
\end{axis}  
\node at (A) {test};
\node at (B) {test 2};% ********* end of changes **********
\end{tikzpicture}
\caption{X}
\label{fig:stats}
\end{figure}
\end{document}