旋转符号将导致其在 LaTeX 中的“pgfplots”图例中空间不正确

Question

有一个triangle符号pgf图。因为有时需要倒三角形，我将其旋转 180 度。它在图中可以正常工作，但在图例中则不行。

\documentclass{article}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}
\usepackage[showframe]{geometry}
%\usetikzlibrary{calc,shapes.arrows,datavisualization,arrows.meta,decorations.pathmorphing,backgrounds,positioning,fit,petri,decorations.pathreplacing}
\begin{document}
\begin{figure}
  \begin{tikzpicture}
    \begin{axis}[xticklabel style={text width=1em},yticklabel style={/pgf/number format/precision =2,/pgf/number format/fixed,/pgf/number format/fixed zerofill},scaled ticks=false,width=7.4cm,height=4cm,xmin=0,xmax=12,ylabel={the third},legend entries={legend1,legend2,legend3} ]
      \addplot[
      scatter,only marks, point meta=explicit symbolic,
      scatter/classes={
        a={mark=o,draw=black},
        b={mark=square*},
        c={mark=triangle*}
      },
      ] table [meta=label]{
        x   y   label
        1   0.55476356  c

        
      };
      \addplot[mark=none, black,dashed,domain=0:12,samples=2] {0.778};
    \end{axis}
  \end{tikzpicture}\\
  \begin{tikzpicture}
    \begin{axis}[xticklabel style={text width=1em},yticklabel style={/pgf/number format/precision =2,/pgf/number format/fixed,/pgf/number format/fixed zerofill},scaled ticks=false,width=7.4cm,height=4cm,xmin=0,xmax=12,ylabel={the third},legend entries={legend1,legend2,legend3} ]
      \addplot[
      scatter,only marks, point meta=explicit symbolic,
      scatter/classes={
        a={mark=o,draw=black},
        b={mark=triangle,rotate=180},
        c={mark=triangle*}
      },
      ] table [meta=label]{
        x   y   label
        1   0.55476356  c

        
      };
      \addplot[mark=none, black,dashed,domain=0:12,samples=2] {0.778};
    \end{axis}
    \end{tikzpicture}
\end{figure}
\end{document}

输出：

是什么原因？

Answer 1

要向绘图标记添加诸如旋转之类的选项，通常应使用mark options（或every mark/.append style），如手动的。但是，由于scatter/classes实施原因，您不能在选项内部使用此功能，但您也不能在环境选项中使用此功能axis，因为您只想旋转一些标记。

因此，最直接的方法可能就是定义一个自定义标记：

\documentclass{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}

\pgfdeclareplotmark{rotated triangle}{%
  \pgfpathmoveto{\pgfqpoint{0pt}{-\pgfplotmarksize}}%
  \pgfpathlineto{\pgfqpointpolar{30}{\pgfplotmarksize}}%
  \pgfpathlineto{\pgfqpointpolar{150}{\pgfplotmarksize}}%
  \pgfpathclose
  \pgfusepathqstroke
}%

\begin{document}
    \begin{tikzpicture}
        \begin{axis}[
            xticklabel style={text width=1em},
            yticklabel style={
                /pgf/number format/precision =2,
                /pgf/number format/fixed,
                /pgf/number format/fixed zerofill
            },
            scaled ticks=false,
            width=7.4cm,
            height=4cm,
            xmin=0, xmax=12,
            ylabel={the third},
            legend entries={legend1, legend2, legend3}
        ]
            \addplot[
                scatter, only marks, point meta=explicit symbolic,
                scatter/classes={
                    a={mark=o, draw=black},
                    b={mark=rotated triangle},
                    c={mark=triangle*}
                }
            ] table [meta=label]{
                x   y   label
                1   0.55476356  c
                2   0.363722187 c
                3   0.81286394  c
                4   0.875783813 c
                5   0.315270863 c
                6   0.827911581 c
                7   0.720070049 c
                8   0.347479399 c
                9   0.27043531  c
                10  0.490422201 c
                11  0.69325892  c
                1   0.735883237 a
                2   0.129003395 a
                3   0.461826926 a
                4   0.756650854 a
                5   0.305755095 a
                6   0.263120301 a
                7   0.38954705  a
                8   0.07894936  a
                9   0.984081129 a
                10  0.712322139 a
                11  0.146583606 a
                1   0.186438911 b
                2   0.483752955 b
                3   0.955453588 b
                4   0.931741157 b
                5   0.307806207 b
                6   0.932585214 b
                7   0.390174549 b
                8   0.397465905 b
                9   0.893646115 b
                10  0.177956892 b
                11  0.250648427 b
          };
          \addplot[mark=none, black,dashed, domain=0:12, samples=2] {0.778};
        \end{axis}
    \end{tikzpicture}
\end{document}

---

同样，您可以定义一个可填充的自定义三角形：

\documentclass{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}

\pgfdeclareplotmark{rotated triangle}{%
  \pgfpathmoveto{\pgfqpoint{0pt}{-\pgfplotmarksize}}%
  \pgfpathlineto{\pgfqpointpolar{30}{\pgfplotmarksize}}%
  \pgfpathlineto{\pgfqpointpolar{150}{\pgfplotmarksize}}%
  \pgfpathclose
  \pgfusepathqstroke
}

\pgfdeclareplotmark{rotated triangle*}{%
  \pgfpathmoveto{\pgfqpoint{0pt}{-\pgfplotmarksize}}%
  \pgfpathlineto{\pgfqpointpolar{30}{\pgfplotmarksize}}%
  \pgfpathlineto{\pgfqpointpolar{150}{\pgfplotmarksize}}%
  \pgfpathclose
  \pgfusepathqfillstroke
}

\begin{document}
    \begin{tikzpicture}
        \begin{axis}[
            xticklabel style={text width=1em},
            yticklabel style={
                /pgf/number format/precision =2,
                /pgf/number format/fixed,
                /pgf/number format/fixed zerofill
            },
            scaled ticks=false,
            width=7.4cm,
            height=4cm,
            xmin=0, xmax=12,
            ylabel={the third},
            legend entries={legend1, legend2, legend3}
        ]
            \addplot[
                scatter, only marks, point meta=explicit symbolic,
                scatter/classes={
                    a={mark=triangle},
                    b={mark=rotated triangle},
                    c={mark=rotated triangle*}
                }
            ] table [meta=label]{
                x   y   label
                1   0.55476356  c
                2   0.363722187 c
                3   0.81286394  c
                4   0.875783813 c
                5   0.315270863 c
                6   0.827911581 c
                7   0.720070049 c
                8   0.347479399 c
                9   0.27043531  c
                10  0.490422201 c
                11  0.69325892  c
                1   0.735883237 a
                2   0.129003395 a
                3   0.461826926 a
                4   0.756650854 a
                5   0.305755095 a
                6   0.263120301 a
                7   0.38954705  a
                8   0.07894936  a
                9   0.984081129 a
                10  0.712322139 a
                11  0.146583606 a
                1   0.186438911 b
                2   0.483752955 b
                3   0.955453588 b
                4   0.931741157 b
                5   0.307806207 b
                6   0.932585214 b
                7   0.390174549 b
                8   0.397465905 b
                9   0.893646115 b
                10  0.177956892 b
                11  0.250648427 b
          };
          \addplot[mark=none, black,dashed, domain=0:12, samples=2] {0.778};
        \end{axis}
    \end{tikzpicture}
\end{document}