我正在尝试使用以下示例显示几个图。我从pgfplots不同于groupplots数据本身的数据文件中获取每个图的标题。数据似乎按照手册指定的正确顺序绘制，但标题未应用于正确的图（例如，“0：0 - 5”应该在右上角）。似乎参数比实际值大一#1，但随后加载了正确的数据列。为什么标题的排序方式与数据不同？
\documentclass{standalone}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
\usepgfplotslibrary{groupplots}
\pgfplotsset{
compat=newest,
every minor tick={very thin, LightGray},
minor tick num=4,
enlargelimits=0.02
}
\pgfplotstableread{
Time {Data 0} {Data 1} {Data 2} {Data 3}
0 7.0 2.3 0.3 1.4
1 6.0 3.6 1.2 2.7
2 5.0 4.8 3.0 3.5
3 4.0 5.9 3.9 7.3
4 3.0 7.3 4.3 6.0
5 2.0 6.5 5.5 7.2
6 1.0 8.9 7.0 8.4
}\datatable
\pgfplotstableread{
Min Max
0 5
6 10
11 15
20 25
}\groupmeta
\begin{document}
\begin{tikzpicture}
\begin{groupplot}[
xlabel={Time},
ylabel={Amplitude},
every axis title shift=0,
% Style list for each plot in order
cycle list={
{only marks, mark=o}
},
group style={group size=2 by 2,
xlabels at=edge bottom,
ylabels at=edge left}]
\pgfplotsinvokeforeach{0,1,2,3}{
% Read in title
\pgfplotstablegetelem{#1}{Min}\of{\groupmeta}
\edef\min{\pgfplotsretval}
\pgfplotstablegetelem{#1}{Max}\of{\groupmeta}
\edef\max{\pgfplotsretval}
% Just to test which element this is...
\def\test{#1}
\nextgroupplot[title=\(\test:\ \min - \max\)]
% Data
\addplot+ table[x index=0, y=Data #1] {\datatable};
}
\end{groupplot}
% Title placement
\node (dummytitle) at ($(group c1r1.north)!0.5!(group c2r1.north)$)
[above]{};
\node (title) at (dummytitle.north)
[above, yshift=\pgfkeysvalueof{/pgfplots/every axis title shift}]
{Experimental Data};
\end{tikzpicture}
\end{document}
答案1
\addplot我相信这与常规 TikZ/PGF 命令和和命令的评估顺序\nextgroupplot被互换有关，尽管直观上这会导致计数器太低。
无论如何，避免这种情况的一个好方法是将命令和title键放入自定义.code键中，如下所示：
set title/.code={
\pgfplotstablegetelem{#1}{Min}\of{\groupmeta}
\edef\min{\pgfplotsretval}
\pgfplotstablegetelem{#1}{Max}\of{\groupmeta}
\edef\max{\pgfplotsretval}
\edef\test{#1}
\pgfplotsset{title=\(\test:\ \min - \max\)}
}
这样，正确的执行顺序就得以保持。你的循环看起来就像
\pgfplotsinvokeforeach{0,1,2,3}{
\nextgroupplot[set title=#1]
\addplot+ table[x index=0, y=Data #1] {\datatable};
}
导致
\documentclass{standalone}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
\usepgfplotslibrary{groupplots}
\pgfplotsset{
compat=newest,
every minor tick={very thin, LightGray},
minor tick num=4,
enlargelimits=0.02
}
\pgfplotstableread{
Time {Data 0} {Data 1} {Data 2} {Data 3}
0 7.0 2.3 0.3 1.4
1 6.0 3.6 1.2 2.7
2 5.0 4.8 3.0 3.5
3 4.0 5.9 3.9 7.3
4 3.0 7.3 4.3 6.0
5 2.0 6.5 5.5 7.2
6 1.0 8.9 7.0 8.4
}\datatable
\pgfplotstableread{
Min Max
0 5
6 10
11 15
20 25
}\groupmeta
\begin{document}
\begin{tikzpicture}
\begin{groupplot}[
set title/.code={
\pgfplotstablegetelem{#1}{Min}\of{\groupmeta}
\edef\min{\pgfplotsretval}
\pgfplotstablegetelem{#1}{Max}\of{\groupmeta}
\edef\max{\pgfplotsretval}
\edef\test{#1}
\pgfplotsset{title=\(\test:\ \min - \max\)}
},
xlabel={Time},
ylabel={Amplitude},
every axis title shift=0,
% Style list for each plot in order
cycle list={
{only marks, mark=o}
},
group style={group size=2 by 2,
xlabels at=edge bottom,
ylabels at=edge left}]
\pgfplotsinvokeforeach{0,1,2,3}{
% Read in title
\nextgroupplot[set title=#1]
% Data
\addplot+ table[x index=0, y=Data #1] {\datatable};
}
\end{groupplot}
% Title placement
\node (dummytitle) at ($(group c1r1.north)!0.5!(group c2r1.north)$)
[above]{};
\node (title) at (dummytitle.north)
[above, yshift=\pgfkeysvalueof{/pgfplots/every axis title shift}]
{Experimental Data};
\end{tikzpicture}
\end{document}