Tikz：配置一组条形图中两个特定条形之间的距离

Question

我有如下所示的分组条形图。

我希望每个红色和蓝色条之间的距离稍微大一点。当然，我可以在红色和蓝色条之间添加另一个白色条 - 但这不是很干净的解决方案，而且会弄乱图例（我试过forget plot在这里使用，但它会让整个条消失）。任何关于如何做到这一点的想法都将不胜感激。

\documentclass{standalone}

\usepackage{pgfplots,pgfplotstable} % plots
\pgfplotsset{compat=newest}

\begin{document}

\begin{tikzpicture}
    \begin{axis}[
        ymax=100,
        ymin=0,
        ybar,
        xtick=data,
        legend style={at={(0.39,0.97)},
           anchor=north,legend columns=2},
        x tick label style={rotate=35,anchor=east},
        symbolic x coords={A, B, C}, 
        bar width=9pt, 
        enlarge x limits=0.2
        ]
                \addplot+[ybar, fill=green] plot coordinates {
                (A, 58.83)
                (B, 50.50)
                (C, 63.67)
                }; 
                \addplot+[ybar, fill=red] plot coordinates {
                (A, 37.83)
                (B, 45.75)
                (C, 34.92)
                };
                \addplot+[ybar, fill=blue] plot coordinates {
                (A, 70.17)
                (B, 59.50)
                (C, 75.17)
                }; 
                 \addplot+[ybar, fill=yellow] plot coordinates {
                (A, 28.50)
                (B, 38.67)
                (C, 23.75)
                };
     \legend{\strut 1st, \strut 2nd, \strut 3rd, \strut 4th}
    \end{axis}
\end{tikzpicture}

\end{document}

Answer 1

\documentclass{standalone}
\usepackage{pgfplots,pgfplotstable} % plots
\pgfplotsset{compat=newest}
\begin{document}
\begin{tikzpicture}
    \begin{axis}[
        ymax=100,
        ymin=0,
        ybar,
        xtick=data,
        legend style={at={(0.39,0.97)},
        anchor=north,legend columns=2},
        x tick label style={rotate=35,anchor=east},
        symbolic x coords={A, B, C}, 
        bar width=9pt, 
        enlarge x limits=0.2
        ]
                \addplot+[ybar, fill=green, bar shift=-20 pt] plot coordinates {
                (A, 58.83)
                (B, 50.50)
                (C, 63.67)
                }; 
                \addplot+[ybar, fill=red, bar shift=-8 pt] plot coordinates {
                (A, 37.83)
                (B, 45.75)
                (C, 34.92)
                };
                \addplot+[ybar, fill=blue, bar shift=8 pt] plot coordinates {
                (A, 70.17)
                (B, 59.50)
                (C, 75.17)
                }; 
                 \addplot+[ybar, fill=yellow, bar shift=20 pt] plot coordinates {
                (A, 28.50)
                (B, 38.67)
                (C, 23.75)
                };
     \legend{\strut 1st, \strut 2nd, \strut 3rd, \strut 4th}
    \end{axis}
\end{tikzpicture}
\end{document}