如何在 pgf 图中显示数据点附近的 x 坐标？

Question

我知道如何使用以下代码显示每个数据点附近的 y 坐标

\documentclass{standalone}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[title={$E_0 $}, ymax=2.5, yticklabels=,
nodes near coords={\pgfmathprintnumber[precision=4]\pgfplotspointmeta},
nodes near coords align={
     shift={(0,1.5cm)},
     rotate=90,
     pin={[pin distance = 0.75cm,
          pin edge={thick,double=yellow}]180:},
     text=red
}
]
  \addplot [blue!90!white, fill=blue!50!white, ybar] coordinates {
    ( 1, 1.96556 )
    ( 2, 1.86105 )
    ( 3, 1.93185 )
    ( 4, 2.02568 )
    ( 5, 2.12077 )
    ( 6, 2.21219 )
  };

\end{axis}
\end{tikzpicture}
\end{document}

实际上，我目前正在使用以下代码来显示所选数据点的 y 坐标。

\documentclass{standalone}
\usepackage{pgfplots}
\begin{document}
\pgfplotsset{
    pin near coord/.style args={#1/#2/#3}{% Style for activating the label for a single coordinate
        scatter/@pre marker code/.append code={
           \ifnum 1=#3
            \ifnum\coordindex=#1 \node[pin={#2:\small\pgfmathprintnumber{\pgfplotspointmeta} }]{};\fi 
            \fi 
            \ifnum 2=#3
            \ifnum\coordindex=#1 \node[pin=#2]{};\fi
            \fi
        }
    },
    pins near some coords/.style={ % Style for activating the label for a list of coordinates
        scatter,
        scatter/@pre marker code/.code={},% Reset the default scatter style, so we don't get coloured markers
        scatter/@post marker code/.code={},% 
        pin near coord/.list={#1} % Run "pin near coord" once for every element in the list
    }
}

\begin{tikzpicture}
\begin{axis}[width=0.9\textwidth]
\addplot [only marks, mark=*] table[each nth point={2}, x=I, y=V, col sep=comma] {vp2.csv};
\addplot [only marks, mark=*, pins near some coords={0/south/1, 1/south/1, 2/south/1, 3/south/1, 4/south/1}  ] table[x=I, y=V, col sep=comma] {minima2.csv};
\end{axis}
\end{tikzpicture}
\end{document}

如何显示 x 坐标？

Answer 1

像这样吗？

\documentclass[tikz,border=3mm]{standalone}
\usepackage{pgfplots}  
\pgfplotsset{compat=1.17}
\begin{document}
\begin{tikzpicture}
\begin{axis}[title={$E_0 $}, ymax=2.5, yticklabels=,
nodes near coords={\pgfmathprintnumber[precision=4]\pgfplotspointmeta},
nodes near coords align={anchor=west,yshift=0.75cm,
     rotate=90,
     pin={[pin distance = 0.75cm,
          pin edge={thick,double=yellow}]180:},
     text=red
}
]
  \addplot [blue!90!white, fill=blue!50!white, ybar] coordinates {
    ( 1, 1.96556 )
    ( 2, 1.86105 )
    ( 3, 1.93185 )
    ( 4, 2.02568 )
    ( 5, 2.12077 )
    ( 6, 2.21219 )
  };

\end{axis}
\end{tikzpicture}
\end{document}