Layout of bar chart + line chart in \subfloat

Question

Edited

I am trying to make my bar charts look nicer than they are now. What I have now:

I would like to:

• Only have the legend at the top graph
• Have the legend depict a single grey bar for 'Weekly PR' (as in picture below)
• Remove the white space on left and right side of the bar charts (but still have a bit of space between bars)
• Have only 1 line node per line on the right of the figure (so it does not conflict with other nodes
• Have all bar nodes be at the same height near the middle of the bar (so they do not conflict with the line)
• Have the name of each set of bar charts be indicated with \subfloat (as it is now)

Legend bar example (red should be grey):

I have a long preamble that is used for many other figures. I've lost track of what does wat exactly, so I include it all here. My code is:

\PassOptionsToPackage{table,dvipsnames,svgnames}{xcolor}
\documentclass[11pt, twoside, a4paper]{report}
\usepackage[inner = 30mm, outer = 20mm,  top = 30mm, bottom = 20mm, headheight = 13.6pt]{geometry}
\usepackage{emptypage}
\usepackage[toc,page]{appendix}
\usepackage{tikz}
\usetikzlibrary{calc,fit,arrows.meta,calc,positioning}
\usepackage{xifthen}
\usepackage[pdfpagelayout=TwoPageRight]{hyperref}
\usepackage{listings}
\usepackage{multicol}
\usepackage{apacite}
\usepackage{color}
\usepackage{textcomp}
\usepackage{chngcntr}
\usepackage[export]{adjustbox}
\hypersetup{colorlinks=true, linktoc=all, allcolors=green!30!black,}
\usepackage{booktabs, siunitx, caption}
\newcommand{\source}[1]{\vspace{-8pt} \caption*{ Source: {#1}} }
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage{slashbox}
\usepackage[caption=false]{subfig}
\usepackage{array}
\newlength\tbspace
\setlength\tbspace{3cm}
\newcolumntype{L}{l<{\hspace{\tbspace}}}

\usepackage{wrapfig}
\graphicspath{ {./Figures/} }
\usepackage{gensymb}
\usepackage{etoolbox}% http://ctan.org/pkg/etoolbox
\makeatletter
\patchcmd{\@makechapterhead}{\vspace*{50\p@}}{}{}{}% Removes space above                \chapter head
\patchcmd{\@makeschapterhead}{\vspace*{50\p@}}{}{}{}% Removes space above               \chapter* head
\makeatother
\usepackage{pgfplots}
\pgfplotsset{compat=1.11,
/pgfplots/ybar legend/.style={
    /pgfplots/legend image code/.code={%
        \draw[##1,/tikz/.cd,yshift=-0.25em]
        (0cm,0cm) rectangle (3pt,0.8em);},},}
\usepgfplotslibrary{statistics}
\usetikzlibrary{arrows}
\usepackage{tcolorbox}
\usepackage{fancyhdr}
\usepackage{layouts}
\usepackage{chronology}
%\usepackage{showframe}
\usepackage{pdfpages}
\raggedbottom
\fancyfoot{}
\fancyhead{}
\fancyfoot[LE]{\thepage}
\fancyfoot[RO]{\thepage}
\fancyhead[LE]{\nouppercase{\leftmark}}
\fancyhead[RO]{\nouppercase{\rightmark}}
\pagestyle{fancy}

%% Redefine the plain page style so chapter pages match my footer preference
\fancypagestyle{plain}{%
\fancyhf{}%
\fancyfoot[LE]{\thepage}
\fancyfoot[RO]{\thepage}
\renewcommand{\headrulewidth}{0pt}% Line at the header invisible
\renewcommand{\footrulewidth}{0pt}% Line at the footer visible
}


\colorlet{A}{gray}
\colorlet{B}{blue!50!black}
\colorlet{C}{white}
\colorlet{D}{black!10}

\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}


%https://tex.stackexchange.com/a/349215
\tikzset{
timeline/.style={arrows={}}%
,timeline style/.style={timeline/.append style={#1}}%
,year label/.style={font=\small\bfseries,below}%                  <- removed \sffamily
,year label style/.style={year label/.append style={#1}}%
,year tick/.style={tick size=0pt}%
,year tick style/.style={year tick/.append style={#1}}%
,minor tick/.style={tick size=0pt, very thin}%
,minor tick style/.style={minor tick/.append style={#1}}%
,period/.style={solid,line width=\timelinewidth,line cap=square}%
,periodbox/.style={font=\small\bfseries,text=black}%              <- removed     \sffamily
,eventline/.style={draw,red,thick,line cap=round,line join=round}%
,eventbox/.style={rectangle,rounded corners=3pt,inner sep=3pt,fill=red!25!white,text width=3cm,anchor=west,text=black,align=left,font=\small}%
,tick size/.code={\def\ticksize{#1}}%
,labeled years step/.code={\def\yearlabelstep{#1}}%
,minor tick step/.code={\def\minortickstep{#1}}%
,year tick step/.code={\def\yeartickstep{#1}}%
,enlarge timeline/.code={\def\enlarge{#1}}%
,eventboxa/.style={eventbox,text width=#1,draw=A,fill=black!10}%
,eventboxb/.style={eventbox,text width=#1,draw=A,fill=none}%
}

% Still from %https://tex.stackexchange.com/a/349215
\newcommand*{\drawtimeline}[5][]{%
\def\fromyear{#2}%
\def\toyear{#3}%
\def\timelinesize{#4}%
\def\timelinewidth{#5}%
\pgfmathsetmacro{\timelinesizept}{\timelinesize}%
\pgfmathsetmacro{\timelinewidthpt}{\timelinewidth}%
\pgfmathsetmacro{\timelineoffset}{\timelinewidth/2}
\pgfmathsetmacro{\timelineoffsetpt}{\timelineoffset}
%
\begin{scope}[x=1pt, y=1pt, % Change main units to pt
    labeled years step=1,% Set some defaults
    minor tick step=0.25,%
    enlarge timeline=0cm,%
    year tick step=1,#1]
    \pgfmathsetmacro{\enlargept}{\enlarge}
    \pgfmathsetmacro{\yearticksep}{\timelinesize/((\toyear-\fromyear)/\yeartickstep)}
    \pgfmathsetmacro{\minorticksep}{\timelinesize/((\toyear-\fromyear)/\minortickstep)}
    \pgfmathsetmacro{\minorticklast}{\minorticksep/\minortickstep}
    \foreach \y[remember=\y as \lasty (initially 0), count=\i from     \fromyear] in {0,\yearticksep,...,\timelinesizept}{
        \coordinate (Y-\i) at (\y,0);
        \draw[year tick] (\y,-\ticksize/2) --  ++(0,\ticksize);
        \ifnum\i=\toyear\breakforeach\else
        \foreach \q[count=\j from 0] in {0,\minorticksep,...,\minorticklast}
        {
            \coordinate (Y-\i-\j) at (\q+\y,0);
            \draw[minor tick] (\q+\y,-\ticksize/2) -- ++(0,\ticksize);
        };\fi};%
    \pgfmathsetmacro{\nextyear}{int(\fromyear+\yearlabelstep)}
    \draw[timeline] (0,0) -- ++(-\enlargept,0) (0,0) -- ++    (\timelinesizept,0) coordinate (end) -- ++(\enlargept,0);% Timeline
    %    \foreach \y in {\fromyear,\nextyear,...,\toyear} \node[year label]     at (Y-\y) {\y};
\end{scope}%

}
% Put a period identifier midway between the start and end of the period

% 1 = color of timeline segment
% 2 = period start
% 3 = period end
% 4 = period text

\newcommand{\period}[5]{\draw[period,#1] (Y-#2) -- (Y-#3)     node[periodbox,#5,midway,text=black] {#4};}


%This somewhat follows @cfr's Chronos. It was certainly inspired by Chronos.
%https://tex.stackexchange.com/a/349236
% 1 = format of line and box
% 2 = year 
% 3 = month
% 4 = day in month
% 5 = pin associated with starting coordinate (well suited to using polar     coordinate)
% 6 = branch at top of pin (well suited to using polar coordinate)
% 7 = Any extra formatting of node
% 8 = Name of node
% 9 = Node content

\newcommand{\vevent}[9]{
\pgfmathtruncatemacro{\syr}{#2}
\pgfmathtruncatemacro{\smth}{#3-1}
\pgfmathsetmacro{\dim}{#4/31}
\ifthenelse{#3=12}{%
    \pgfmathtruncatemacro{\fyr}{#2+1}
    \pgfmathtruncatemacro{\fmth}{0}
}{%
    \pgfmathtruncatemacro{\fyr}{#2}
    \pgfmathtruncatemacro{\fmth}{#3}
}
\draw[eventline,#1]($(Y-\syr-\smth)!\dim!(Y-\fyr-\fmth)$) -- ++(#5) -- ++(#6) node[#7] (#8) {#9};
}

% https://tex.stackexchange.com/questions/255298/draw-rectangular-nodes-defined-by-opposing-corner-coordinates-with-vertically-ce
\tikzset{
block/.style 2 args = {text = white,
    draw=none, inner sep=0, outer sep=0,
    rounded corners=3pt,
    fit=(#1) (#2)}
}

\newcommand{\fnode}[4][]{
\coordinate (bottom left) at (#2);
\coordinate (top right) at (#3);
\node[block={bottom left}{top right}, #1, label=center:#4] {};
}

\tikzset{
raisewheel/.style={
    execute at end picture={
        \path (-90:#1*\outerradius);
    }
},
raisewheel/.default=1.3
}
\begin{filecontents}{installations.csv}
Name,   Quantity
"Japan", 66
"China", 12
"Korea", 8
"Other", 23
\end{filecontents}

\begin{filecontents}{installedcapacity.csv}
Name,   Quantity
"Japan", 95.516
"China", 394.258
"Korea", 16.901
"Other", 14.589
\end{filecontents}

\begin{document}

\begin{figure}
\subfloat[System 1]{%   
    \begin{tikzpicture}
    \begin{axis}[
    width=\linewidth,
    height=0.35\linewidth,
    bar width=25pt, enlarge x limits=0.15, ymin=0, 
    legend style={at={(0.5,1.15)},anchor=north,legend columns=2},
    ylabel={PR\textsubscript{A}},
    xtick=data, nodes near coords,  axis lines*=left, ymajorgrids
    ]
    \addplot[ybar, red!50!black, fill=white!70!black] coordinates {(17,0.926) (18, 0.940) (19, 0.862) (20, 0.849) (21, 0.871) (22,0.894) (23,0.903) (24,0.885) (25,0.892) (26,0.837) (27,0.814) (28,0.818) (29,0.810)};
    \addplot[draw = black, ultra thick, smooth] coordinates {(17,0.869) (18, 0.869) (19, 0.869) (20, 0.869) (21, 0.869) (22,0.869) (23,0.869) (24,0.869) (25,0.869) (26,0.869) (27,0.869) (28,0.869) (29,0.869)};
    \legend{Weekly PR, Average over test period}
    \end{axis}
    \end{tikzpicture}
}

\subfloat[System 2]{%   
    \begin{tikzpicture}
    \begin{axis}[
    width=\linewidth,
    height=0.35\linewidth,
    bar width=25pt, enlarge x limits=0.15, ymin=0, 
    legend style={at={(0.5,1.15)},anchor=north,legend columns=2},
    ylabel={PR\textsubscript{A}},
    xtick=data, nodes near coords,  axis lines*=left, ymajorgrids
    ]
    \addplot[ybar, blue!50!black, fill=white!70!black] coordinates {(17,0.923) (18, 0.921) (19, 0.857) (20, 0.867) (21, 0.886) (22,0.880) (23,0.886) (24,0.888) (25,0.893) (26,0.826) (27,0.818) (28,0.857) (29,0.848)};
    \addplot[draw = black, ultra thick, smooth] coordinates {(17,0.873) (18, 0.873) (19, 0.873) (20, 0.873) (21, 0.873) (22,0.873) (23,0.873) (24,0.873) (25,0.873) (26,0.873) (27,0.873) (28,0.873) (29,0.873)};
    \legend{Weekly PR, Average over test period}
    \end{axis}
    \end{tikzpicture}
}

\subfloat[System 3]{%   
    \begin{tikzpicture}
    \begin{axis}[
    width=\linewidth,
    height=0.35\linewidth,
    bar width=25pt, enlarge x limits=0.15, ymin=0, 
    legend style={at={(0.5,1.15)},anchor=north,legend columns=2},
    ylabel={PR\textsubscript{A}},
    xtick=data, nodes near coords,  axis lines*=left, ymajorgrids
    ]
    \addplot[ybar, green!50!black, fill=white!70!black] coordinates {(17,0.915) (18, 0.912) (19, 0.840) (20, 0.845) (21, 0.873) (22,0.868) (23,0.875) (24,0.877) (25,0.883) (26,0.812) (27,0.789) (28,0.840) (29,0.833)};
    \addplot[draw =black, ultra thick, smooth] coordinates {(17,0.859) (18, 0.859) (19, 0.859) (20, 0.859) (21, 0.859) (22,0.859) (23,0.859) (24,0.859) (25,0.859) (26,0.859) (27,0.859) (28,0.859) (29,0.859)};
    \legend{Weekly PR, Average over test period}
    \end{axis}
    \end{tikzpicture}
}

\subfloat[System 4]{%   
    \begin{tikzpicture}
    \begin{axis}[
    width=\linewidth,
    height=0.35\linewidth,
    bar width=25pt, enlarge x limits=0.15, ymin=0,
    legend style={at={(0.5,1.15)},anchor=north,legend columns=2}, 
    ylabel={PR\textsubscript{A}},
    xlabel={Week of 2018},
    xtick=data, nodes near coords,  axis lines*=left, ymajorgrids
    ]
    \addplot[ybar, black, fill=white!70!black] coordinates {(17,0.926) (18, 0.940) (19, 0.862) (20, 0.849) (21, 0.871) (22,0.894) (23,0.903) (24,0.885) (25,0.892) (26,0.837) (27,0.814) (28,0.818) (29,0.810)};
    \addplot[draw = black, ultra thick, smooth] coordinates {(17,0.869) (18, 0.869) (19, 0.869) (20, 0.869) (21, 0.869) (22,0.869) (23,0.869) (24,0.869) (25,0.869) (26,0.869) (27,0.869) (28,0.869) (29,0.869)};
    \legend{Weekly PR, Average over test period}
    \end{axis}
\end{tikzpicture}
}
\caption{Performance ratios for reference system}
\label{fig:PRs ref syst}
\end{figure}
\end{document}

Answer 1

I guess you are searching for something similar to the following code. Because you had a lot of requirements and your code was quite "suboptimal", I will not go into details here, but you will find detailed explanations in the comments in the code.

Please note that I have removed the figure environment and the \subfloat commands, because they are not relevant to answer your question.

% used PGFPlots v1.16
\documentclass[border=5pt,varwidth]{standalone}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
    \pgfplotsset{
        compat=1.16,
        % created a style for the common `axis' options
        my axis style/.style={
            width=\linewidth,
            height=0.35\linewidth,
            bar width=0.9,
            enlarge x limits={abs=0.45},    % <-- changed to absolute coordinates
            ymin=0,
            legend style={
                at={(0.5,1.05)},    % <-- adapted
                anchor=south,       % <-- changed from `north'
                legend columns=2,
            },
            ylabel={PR\textsubscript{A}},
            xtick=data,
            axis lines*=left,
            ymajorgrids,
            %
            table/x=x,
        },
        % created a style for the common `ybar' options
        my ybar style/.style={
            ybar,
            my ybar legend,            % <-- change legend image accordingly
            #1!50!black,
            fill=white!70!black,
            nodes near coords,      % <-- moved from `axis' options here
            % state absolute positions for the `nodes near coords'
            scatter/position=absolute,
            node near coords style={
                % state where the nodes should appear
                at={(\pgfkeysvalueof{/data point/x},0.5)},
                anchor=center,
                % make the font a bit smaller
                font=\footnotesize,
                % set the number format of the `nodes near coords'
                /pgf/number format/.cd,
                    fixed,
                    precision=3,
                    zerofill,
            },
        },
        my ybar legend/.style={
            /pgfplots/legend image code/.code={
                \draw [
                    ##1,
                    /tikz/.cd,
                    yshift=-0.25em,
                ] (0cm,0cm) rectangle (3pt,0.8em);
            },
        },
    }
    % define a command for the "node near coord" for the line
    \newcommand*\LineNode{
        % add a node at the end of the line
        node [pos=1,above] {
            % get the (axis) coordinates of the last coordinate
            \pgfplotspointgetcoordinates{(current plot end)}
            % print the y value in the given number format
            $\pgfmathprintnumber[
                fixed,
                precision=3,
                zerofill,
            ]{
                \pgfkeysvalueof{/data point/y}}$
        }
    }
    % created a table for the data which is much easier to maintain
    % (this can also be exported to a file)
    \pgfplotstableread{
        x     y1       y2       y3      y4
        17    0.926    0.923    0.915   0.926
        18    0.940    0.921    0.912   0.940
        19    0.862    0.857    0.840   0.862
        20    0.849    0.867    0.845   0.849
        21    0.871    0.886    0.873   0.871
        22    0.894    0.880    0.868   0.894
        23    0.903    0.886    0.875   0.903
        24    0.885    0.888    0.877   0.885
        25    0.892    0.893    0.883   0.892
        26    0.837    0.826    0.812   0.837
        27    0.814    0.818    0.789   0.814
        28    0.818    0.857    0.840   0.818
        29    0.810    0.848    0.833   0.810
    }{\loadedtable}
\begin{document}
\begin{tikzpicture}
    \begin{axis}[
        % removed all single options and replaced them by the created style
        my axis style,
    ]
        \addplot [
            % removed all single options and replaced them by the created style
            my ybar style=red,
        % changed from `coordinates' to `table' + corresponding option
        ] table [y=y1] {\loadedtable};
        % heavily simplified by removing unnecessary options and coordinates
        % (a straight line only needs two coordinates)
        \addplot [ultra thick] coordinates {(17,0.869) (29,0.869)}
            % add the node of the line
            \LineNode
        ;
        \legend{Weekly PR, Average over test period}
    \end{axis}
\end{tikzpicture}

\begin{tikzpicture}
    \begin{axis}[
        my axis style,
    ]
        \addplot [
            my ybar style=blue,
        ] table [y=y2] {\loadedtable};
        \addplot [ultra thick] coordinates {(17,0.873) (29,0.873)}
            \LineNode
        ;
        % if you don't want to show a legend here, remove the command
    \end{axis}
\end{tikzpicture}

\begin{tikzpicture}
    \begin{axis}[
        my axis style,
    ]
        \addplot [
            my ybar style=green,
        ] table [y=y3] {\loadedtable};
        \addplot [ultra thick] coordinates {(17,0.859) (29,0.859)}
            \LineNode
        ;
    \end{axis}
\end{tikzpicture}

\begin{tikzpicture}
    \begin{axis}[
        my axis style,
    ]
        \addplot [
            my ybar style=black,
            draw=black,     % <-- here you break the "rule" so restate it
        ] table [y=y4] {\loadedtable};
        \addplot [ultra thick] coordinates {(17,0.869) (29,0.869)}
            \LineNode
        ;
    \end{axis}
\end{tikzpicture}
\end{document}