我想绘制一个有两个 x 轴（顶部和底部）和一个 y 轴的数据。第一个 x 轴和 y 轴是从数据中设置的。第二个 x 轴的限制应该与第一个相同。我还需要在第二个 x 轴上标记一些刻度。Pgfplots 不允许我标记（见图）。
我怎样才能取得成果？
\documentclass[12pt,a4paper]{article}%
\usepackage{pgfplots}
\usepackage{filecontents}
\def\w{11}
\def\h{10}
\begin{filecontents*}{mydata.csv}
0,0,0
0.5963459,1.402948075,0
1.1520177,2.71020725,0
1.6688749,3.9261522,0
2.148838675,5.055302625,0
2.593862225,6.1022536,0
3.0059051,7.0716151,0
3.386911525,7.967961025,0
3.854113525,8.763110075,0.30397835
4.7655312,9.359200525,1.8520657
5.6033659,9.907176575,3.27515805
6.73565105,10.2090156,4.570585925
7.803365275,10.46821083,5.760149325
8.782843025,10.70411198,6.852623
9.6808764,10.91879745,7.855273375
10.50381463,11.11416708,8.7749295
11.25757995,11.29195553,9.617991625
11.91476308,11.35993613,10.04455928
12.51314918,11.4149591,10.41695778
24.97249018,14.50643975,15.46234698
24.97679915,14.50785408,15.4627031
24.98072545,14.5091428,15.46302755
24.984303,14.51031708,15.46332318
24.9875628,14.51138705,15.46359253
24.99053308,14.512362,15.46383795
24.99323953,14.51325038,15.46406155
24.99570558,14.51405983,15.46426528
24.99795258,14.51479738,15.46445093
25,14.51546943,15.46462005
\end{filecontents*}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
width=\w cm, height=\h cm,
scale only axis,
axis x line*=bottom,
axis y line*=left,
table/x index={0},thick,
xlabel=$x$,
ylabel=$y$,
]
\foreach \ind in {1,2}{
\addplot table[y index={\ind}, col sep=comma, mark=none] {mydata.csv};
}
\end{axis}
%%%%%%%%%%
\begin{axis}[
width=\w cm, height=\h cm,
scale only axis,thick,
axis x line*=top,
axis y line*=right,
xtick={3,7},
xticklabels={a,b},
yticklabels=none
]
\end{axis}
\end{tikzpicture}
\end{document}
答案1
更新：如果您确实只想添加 a 和 b 标签，则不需要所有双轴技巧。
\documentclass[12pt,a4paper]{article}%
\usepackage{pgfplots}
\usepackage{filecontents}
\def\w{11}
\def\h{10}
\begin{filecontents*}{mydata.csv}
0,0,0
0.5963459,1.402948075,0
1.1520177,2.71020725,0
1.6688749,3.9261522,0
2.148838675,5.055302625,0
2.593862225,6.1022536,0
3.0059051,7.0716151,0
3.386911525,7.967961025,0
3.854113525,8.763110075,0.30397835
4.7655312,9.359200525,1.8520657
5.6033659,9.907176575,3.27515805
6.73565105,10.2090156,4.570585925
7.803365275,10.46821083,5.760149325
8.782843025,10.70411198,6.852623
9.6808764,10.91879745,7.855273375
10.50381463,11.11416708,8.7749295
11.25757995,11.29195553,9.617991625
11.91476308,11.35993613,10.04455928
12.51314918,11.4149591,10.41695778
24.97249018,14.50643975,15.46234698
24.97679915,14.50785408,15.4627031
24.98072545,14.5091428,15.46302755
24.984303,14.51031708,15.46332318
24.9875628,14.51138705,15.46359253
24.99053308,14.512362,15.46383795
24.99323953,14.51325038,15.46406155
24.99570558,14.51405983,15.46426528
24.99795258,14.51479738,15.46445093
25,14.51546943,15.46462005
\end{filecontents*}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
width=\w cm, height=\h cm,
scale only axis,
table/x index={0},thick,
xlabel=$x$,
ylabel=$y$,
]
\foreach \ind in {1,2}{
\addplot table[y index={\ind}, col sep=comma, mark=none] {mydata.csv};
}
\coordinate (3) at (axis cs:3,0);
\coordinate (7) at (axis cs:7,0);
\end{axis}
\draw[thin] (3 |- current axis.north east) node[above] {a} -- ++(0,-4pt);
\draw[thin] (7 |- current axis.north east) node[above] {b} -- ++(0,-4pt);
%%%%%%%%%%
\end{tikzpicture}
\end{document}
旧答案：
\documentclass[12pt,a4paper]{article}%
\usepackage{pgfplots}
\usepackage{filecontents}
\def\w{11}
\def\h{10}
\begin{filecontents*}{mydata.csv}
0,0,0
0.5963459,1.402948075,0
1.1520177,2.71020725,0
1.6688749,3.9261522,0
2.148838675,5.055302625,0
2.593862225,6.1022536,0
3.0059051,7.0716151,0
3.386911525,7.967961025,0
3.854113525,8.763110075,0.30397835
4.7655312,9.359200525,1.8520657
5.6033659,9.907176575,3.27515805
6.73565105,10.2090156,4.570585925
7.803365275,10.46821083,5.760149325
8.782843025,10.70411198,6.852623
9.6808764,10.91879745,7.855273375
10.50381463,11.11416708,8.7749295
11.25757995,11.29195553,9.617991625
11.91476308,11.35993613,10.04455928
12.51314918,11.4149591,10.41695778
24.97249018,14.50643975,15.46234698
24.97679915,14.50785408,15.4627031
24.98072545,14.5091428,15.46302755
24.984303,14.51031708,15.46332318
24.9875628,14.51138705,15.46359253
24.99053308,14.512362,15.46383795
24.99323953,14.51325038,15.46406155
24.99570558,14.51405983,15.46426528
24.99795258,14.51479738,15.46445093
25,14.51546943,15.46462005
\end{filecontents*}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
width=\w cm, height=\h cm,
scale only axis,
axis x line*=bottom,
axis y line*=left,
table/x index={0},thick,
xlabel=$x$,
ylabel=$y$,
]
\foreach \ind in {1,2}{
\addplot table[y index={\ind}, col sep=comma, mark=none] {mydata.csv};
}
\end{axis}
%%%%%%%%%%
\begin{axis}[
width=\w cm, height=\h cm,
scale only axis,thick,
axis x line*=top,
axis y line*=right,
xtick={3,7},
xticklabels={a,b},
yticklabels=none
]
\foreach \ind in {1,2}{
\addplot[opacity=0] table[y index={\ind}, col sep=comma, mark=none] {mydata.csv};
}
\end{axis}
\end{tikzpicture}
\end{document}
