为分组堆积条形图中的所有图表仅添加一个图例

Question

我想为 3 个图创建一个简单的分组堆叠条形图。这是我的代码：

\documentclass[tikz,border=5mm]{standalone}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}[
  every axis/.style={
          ybar stacked,
          legend pos=north west, ymin=0, ymax = 10,
          bar width=3pt,
          x tick label style={rotate=45,anchor=east}
  }
]

\begin{axis}[bar shift=-9pt, legend style = {name = serieA}]
  \addplot [fill=blue] coordinates {
  (1,2)
  (2,3)};
  \addlegendentry{$a$}
\end{axis}

\begin{axis}[bar shift=-6pt, hide axis, legend style = {at = {([xshift=0.5mm, yshift = 2.9mm]serieA)}}]
  \addplot [fill=orange] coordinates {
  (1,4)
  (2,5)};
  \addlegendentry{$b$}
\end{axis}

\begin{axis}[bar shift=-3pt, hide axis, legend style = {at = {([xshift=10mm, yshift = 2.9mm]serieA)}}]
  \addplot [fill=green] coordinates {
  (1,6)
  (2,7)};
  \addlegendentry{$c$}
\end{axis}

\end{tikzpicture}

\end{document}

结果是：

如您所见，有三个图例 a、b、c，它们彼此分开。我希望只有一个图例包含所有这三个图例。

Answer 1

• 这不是堆叠图...
• 你的代码可以简化
• 对于数据使用pgfplotstable包

\documentclass[border=3mm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.17}
\usepackage{pgfplotstable}

\begin{document}
    \begin{tikzpicture}
\pgfplotstableread{
    X       a   b   c
    1       2   4   6
    2       3   5   7
                 }\mydata
\begin{axis}[
    ybar=0.4mm,     % distance between bars (shift bar)
    bar width=4mm,  % width of bars
    ymin=0, ymax=10,
%
    xtick=data,
    xticklabels from table = {\mydata}{X},
    enlarge x limits = 0.4,
%
    legend style = {legend columns=-1,
                    legend pos=north west,
                    font=\footnotesize,
                    /tikz/every even column/.append style={column sep=2mm},
                    },
    ]
\addplot table[x expr=\coordindex,y index=1] {\mydata};
\addplot table[x expr=\coordindex,y index=2] {\mydata};
\addplot table[x expr=\coordindex,y index=3] {\mydata};

  \legend{$a$, $b$, $c$}
\end{axis}
    \end{tikzpicture}
\end{document}

Answer 2

在这里，我根据这里提供的解决方案改编了这个答案：pgfplots：一个图表中的多个（移位）堆叠图

梅威瑟：

\documentclass[tikz,border=5mm]{standalone}
\usepackage{pgfplots}

% from https://tex.stackexchange.com/questions/13627/pgfplots-multiple-shifted-stacked-plots-in-one-diagram
\makeatletter
\newcommand\resetstackedplots{
\makeatletter
\pgfplots@stacked@isfirstplottrue
\makeatother
\addplot [forget plot,draw=none] coordinates{(1,0) (2,0) (3,0)};
}
\makeatother

\begin{document}

    \begin{tikzpicture}
        \begin{axis}[
            ybar stacked,
            legend pos=north west, ymin=0, ymax = 10,
            bar width=3pt,
            xmax = 2.1,
            x tick label style={rotate=45,anchor=east},
            legend entries = {a,b,c},
            ]
        
            \addplot [fill=blue, bar shift=-9pt] coordinates {
            (1,2)
            (2,3)};
            \resetstackedplots
            
            \addplot [fill=orange, bar shift=-6pt] coordinates {
            (1,4)
            (2,5)};
            \resetstackedplots
            
            \addplot [fill=green, bar shift=-3pt] coordinates {
            (1,6)
            (2,7)};
            \resetstackedplots
        
        \end{axis}
    \end{tikzpicture}


\end{document}