我有一个图，我想在其中添加图例，该图例是线条和标记的组合。为此，我想替换（或定义新的）原始 pgf 图例类型。如前所述，在下面的 MWE 中，我想将图中的图例替换为类似于图形下方的图例，并使用与图形中相同的符号和线条。这可能吗？
\documentclass[10pt,border=0pt]{standalone}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{tikz}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
\pgfplotstableread{%
x0 y1 y2 y3 y4 y5 y6
1 3.1 3.1 1.8 2.4 1.6 0.7
3 3.2 2.8 1.8 2.2 1.7 0.5
5 3.3 3.0 1.6 2.6 1.4 0.3
7 3.1 3.0 1.2 2.7 1.5 0.2
9 3.0 2.9 1.5 2.5 1.3 0.2
}{\testdata}
\usetikzlibrary{arrows}
\usetikzlibrary{plotmarks}
% mytick x interval=xmin:xstep:xmax
\pgfplotsset{mytick x interval/.style args={#1:#2:#3}{%
xmin=#1,xmax=#3,xincrement={#1}{#2},
xtick={#1,\xval,...,#3}
},
xincrement/.code 2 args={\pgfmathparse{#1+#2}\xdef\xval{\pgfmathresult}}
}
% mytick y interval=ymin:ystep:ymax
\pgfplotsset{mytick y interval/.style args={#1:#2:#3}{%
ymin=#1,ymax=#3,yincrement={#1}{#2},
ytick={#1,\yval,...,#3}
},
yincrement/.code 2 args={\pgfmathparse{#1+#2}\xdef\yval{\pgfmathresult}}
}
\pgfplotsset{every tick/.style={black,}}
\pgfplotsset{%
compat=1.8,
compat/show suggested version=false,
mytick x interval=1:2:9,
mytick y interval=0:0.5:4,
tick label style={font=\footnotesize},
label style={font=\footnotesize},
xlabel={x-label},
ylabel={y-label},
%enlargelimits=false,
legend style={%
font=\footnotesize,
legend cell align=left,
legend pos=south east,
nodes={inner xsep=2pt,inner ysep=0.4pt,text depth=0.15em},
},
}
\begin{document}
\begin{tikzpicture}
\begin{axis}[%
legend entries={%
A,
B,
C,
S1,
S2,
},
mark options={fill=white,solid},
]
\addlegendimage{thick,only marks,mark=square*} \label{c1}
\addlegendimage{thick,only marks,mark=triangle*} \label{c2}
\addlegendimage{thick,only marks,mark=*} \label{c3}
\addlegendimage{thick} \label{l1}
\addlegendimage{thick,dashed} \label{l2}
%
\addplot[thick,mark=square*] table[x=x0,y=y2] {\testdata}; \label{n1}
\addplot[thick,dashed,mark=square*] table[x=x0,y=y1] {\testdata}; \label{n2}
\addplot[thick,mark=triangle*] table[x=x0,y=y4] {\testdata}; \label{n3}
\addplot[thick,dashed,mark=triangle*] table[x=x0,y=y3] {\testdata}; \label{n4}
\addplot[thick,mark=*] table[x=x0,y=y6] {\testdata}; \label{n5}
\addplot[thick,dashed,mark=*] table[x=x0,y=y5] {\testdata}; \label{n6}
\end{axis}
\end{tikzpicture}
\begin{tabular}{llll}
& & S1 & S2 \\
& & \ref{l1} & \ref{l2} \\
A & \ref{c1} & \ref{n1} & \ref{n2} \\
B & \ref{c2} & \ref{n3} & \ref{n4} \\
C & \ref{c3} & \ref{n5} & \ref{n6} \\
\end{tabular}
\end{document}
答案1
我发现最好的方法是使用一个\usetikzlibrary{matrix}在其周围绘制边框的矩阵（...draw,）并引用轴...anchor=south east] at (rel axis cs: 0.97,0.03)
注意：要收紧边界框，您需要inner sep减少矩阵为零，但强制其为大于零的值节点，请参阅以下方括号内的代码\matrix(dict)：
\documentclass[10pt,border=0pt]{standalone}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{tikz}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
\pgfplotstableread{%
x0 y1 y2 y3 y4 y5 y6
1 3.1 3.1 1.8 2.4 1.6 0.7
3 3.2 2.8 1.8 2.2 1.7 0.5
5 3.3 3.0 1.6 2.6 1.4 0.3
7 3.1 3.0 1.2 2.7 1.5 0.2
9 3.0 2.9 1.5 2.5 1.3 0.2
}{\testdata}
\usetikzlibrary{arrows}
\usetikzlibrary{plotmarks}
\usetikzlibrary{matrix} %added
% mytick x interval=xmin:xstep:xmax
\pgfplotsset{mytick x interval/.style args={#1:#2:#3}{%
xmin=#1,xmax=#3,xincrement={#1}{#2},
xtick={#1,\xval,...,#3}
},
xincrement/.code 2 args={\pgfmathparse{#1+#2}\xdef\xval{\pgfmathresult}}
}
% mytick y interval=ymin:ystep:ymax
\pgfplotsset{mytick y interval/.style args={#1:#2:#3}{%
ymin=#1,ymax=#3,yincrement={#1}{#2},
ytick={#1,\yval,...,#3}
},
yincrement/.code 2 args={\pgfmathparse{#1+#2}\xdef\yval{\pgfmathresult}}
}
\pgfplotsset{every tick/.style={black,}}
\pgfplotsset{%
compat=1.8,
compat/show suggested version=false,
mytick x interval=1:2:9,
mytick y interval=0:0.5:4,
tick label style={font=\footnotesize},
label style={font=\footnotesize},
xlabel={x-label},
ylabel={y-label},
%enlargelimits=false,
legend style={%
font=\footnotesize,
legend cell align=left,
legend pos=south east,
nodes={inner xsep=2pt,inner ysep=0.4pt,text depth=0.15em},
},
}
\begin{document}
\begin{tikzpicture}
\begin{axis}[%
]
%
\addplot[thick,mark=square*] table[x=x0,y=y2] {\testdata}; \label{n1}
\addplot[thick,dashed,mark=square*] table[x=x0,y=y1] {\testdata}; \label{n2}
\addplot[thick,mark=triangle*] table[x=x0,y=y4] {\testdata}; \label{n3}
\addplot[thick,dashed,mark=triangle*] table[x=x0,y=y3] {\testdata}; \label{n4}
\addplot[thick,mark=*] table[x=x0,y=y6] {\testdata}; \label{n5}
\addplot[thick,dashed,mark=*] table[x=x0,y=y5] {\testdata}; \label{n6}
%legend images that aren't actually plotted
\addlegendimage{thick, solid};\label{l1}
\addlegendimage{thick, dashed};\label{l2}
\addlegendimage{only marks, mark=square*};\label{c1}
\addlegendimage{only marks, mark=triangle*};\label{c2}
\addlegendimage{only marks, mark=*};\label{c3}
\end{axis}
\matrix(dict)[ inner sep=0pt,outer sep=0pt,draw,%necessary to move "border" in so it tightly bounds all nodes
matrix of nodes, %eliminates need to surround text with \node{<text>}
%nodes={draw},%draw boxes around all nodes (for debugging)
every node/.style={inner ysep=2pt,inner xsep=4pt},%need to set the "inner sep" of NODES to >0 so they are spaced
fill=white,
anchor=south east
] at (rel axis cs: 0.97,0.03){%places the "legend" so its southeast corner is just within the tick marks
& & S1 & S2 \\
& & \ref{l1} & \ref{l2} \\
A & \ref{c1} & \ref{n1} & \ref{n2} \\
B & \ref{c2} & \ref{n3} & \ref{n4} \\
C & \ref{c3} & \ref{n5} & \ref{n6} \\
};
\end{tikzpicture}
\end{document}
输出：
