我正在按照解释 pgfplots groupplots 中的两个 x 轴，一个在另一个之下但是当情节有两列时，我无法做出同样的事情。
我需要将上部 x 轴上的 0 Hz 刻度与下部 x 轴上的 0 rad/s 刻度相匹配，并且将上部 x 轴上的 1 Hz 刻度与下部 x 轴上的 2*pi rad/s 刻度相匹配。
我的代码如下。我在每个图中只留下了两个点。它们看起来是空的。
有什么建议吗？
\documentclass{standalone}
\usepackage{filecontents}
\usepackage{pgfplots}
\usepgfplotslibrary{groupplots,units}
\pgfplotsset{compat=1.14}
\begin{filecontents*}{ArbitraryPhaseUncontrolledMag_s21_prototype.csv}
freq,s21_dB
0.01,-0.11462467235855
1,-64.67870768049613
\end{filecontents*}
\begin{filecontents*}{ArbitraryPhaseUncontrolledMag_s11_prototype.csv}
freq,s11_dB
0.01,-15.84224832175662
1,-1.478814217873018e-06
\end{filecontents*}
\begin{filecontents*}{ArbitraryPhaseUncontrolledMag_gd_prototype.csv}
freq,group_delay
0.01495,2.587062551091017
1,0.05680967942229484
\end{filecontents*}
\begin{document}
\begin{tikzpicture}
\begin{groupplot}[
group style={
group size=2 by 2,
horizontal sep=2cm,
vertical sep=0.7cm,
xlabels at=edge bottom,
ylabels at=edge left,
},
% scale only axis,
% scaled x ticks=false,
% change x base,
% x unit=Hz,
% xlabel={Frequency},
grid=major,
]
\nextgroupplot[
ylabel=$ S_{21} $,
x unit=Hz,
xlabel={Frequency},
]
\addplot[blue] table[x=freq,y=s21_dB,col sep=comma] {ArbitraryPhaseUncontrolledMag_s21_prototype.csv};
\addplot[red] table[x=freq,y=s11_dB,col sep=comma] {ArbitraryPhaseUncontrolledMag_s11_prototype.csv};
\nextgroupplot[
ylabel=$ \tau_{g} $,
x unit=Hz,
xlabel={Frequency},
]
\addplot[blue] table[x=freq,y=group_delay,col sep=comma] {ArbitraryPhaseUncontrolledMag_gd_prototype.csv};
\nextgroupplot[
axis y line=none,
axis x line*=bottom,
grid=none,
xlabel=Frequency,
x unit=rad/s,
xmin=0,
xmax=2*pi,
xtick={0,0.2*2*pi,0.4*2*pi,0.6*2*pi,0.8*2*pi,2*pi},
height=2.3cm
]
\nextgroupplot[
axis y line=none,
axis x line*=bottom,
grid=none,
xlabel=Frequency,
x unit=rad/s,
xmin=0,
xmax=2*pi,
xtick={0,0.2*2*pi,0.4*2*pi,0.6*2*pi,0.8*2*pi,2*pi},
height=2.3cm
]
\end{groupplot}
\end{tikzpicture}
\end{document}
答案1
如果你width在组图中添加一个选项，那么你将获得一个适当大小的额外轴。在下面的代码中，我使用了
width=.45\textwidth,
您还需要强制enlargelimits=true与主图中的样式相匹配。请注意width=.4\textwidth，像我最初所做的那样，减少到确实留出了足够的空间来打印所有刻度，因此pgfplots会忽略您在这种大小下的刻度规范。
\documentclass{article}
\usepackage{filecontents}
\usepackage{pgfplots}
\usepgfplotslibrary{groupplots,units}
\pgfplotsset{compat=1.14}
\begin{filecontents*}{ArbitraryPhaseUncontrolledMag_s21_prototype.csv}
freq,s21_dB
0.01,-0.11462467235855
1,-64.67870768049613
\end{filecontents*}
\begin{filecontents*}{ArbitraryPhaseUncontrolledMag_s11_prototype.csv}
freq,s11_dB
0.01,-15.84224832175662
1,-1.478814217873018e-06
\end{filecontents*}
\begin{filecontents*}{ArbitraryPhaseUncontrolledMag_gd_prototype.csv}
freq,group_delay
0.01495,2.587062551091017
1,0.05680967942229484
\end{filecontents*}
\begin{document}
\begin{tikzpicture}
\begin{groupplot}[
group style={
group size=2 by 2,
horizontal sep=2cm,
vertical sep=0.7cm,
xlabels at=edge bottom,
ylabels at=edge left,
},
width=.4\textwidth,
scale only axis,
scaled x ticks=false,
change x base,
x unit=Hz,
xlabel={Frequency},
grid=major,
]
\nextgroupplot[
ylabel=$ S_{21} $,
x unit=Hz,
xlabel={Frequency},
]
\addplot[blue] table[x=freq,y=s21_dB,col sep=comma] {ArbitraryPhaseUncontrolledMag_s21_prototype.csv};
\addplot[red] table[x=freq,y=s11_dB,col sep=comma] {ArbitraryPhaseUncontrolledMag_s11_prototype.csv};
\nextgroupplot[
ylabel=$ \tau_{g} $,
x unit=Hz,
xlabel={Frequency},
]
\addplot[blue] table[x=freq,y=group_delay,col sep=comma] {ArbitraryPhaseUncontrolledMag_gd_prototype.csv};
\nextgroupplot[
axis y line=none,
axis x line*=bottom,
grid=none,
xlabel=Frequency,
x unit=rad/s,
xmin=0,
xmax=2*pi,
xtick={0,0.2*2*pi,0.4*2*pi,0.6*2*pi,0.8*2*pi,2*pi},
height=2.3cm,
enlargelimits=true
]
\nextgroupplot[
axis y line=none,
axis x line*=bottom,
grid=none,
xlabel=Frequency,
x unit=rad/s,
xmin=0,
xmax=2*pi,
xtick={0,0.2*2*pi,0.4*2*pi,0.6*2*pi,0.8*2*pi,2*pi},
height=2.3cm,
enlargelimits=true
]
\end{groupplot}
\end{tikzpicture}
\end{document}
\pgfplotsset可以组合几个选项，特别是对于新注释中的标签样式，并且可以通过直接使用和引入自己的样式命令来缩短代码，如下所示：
\documentclass{article}
\usepackage{filecontents}
\usepackage{pgfplots}
\usepgfplotslibrary{groupplots,units}
\pgfplotsset{compat=1.15}
\begin{filecontents*}{ArbitraryPhaseUncontrolledMag_s21_prototype.csv}
freq,s21_dB
0.01,-0.11462467235855
1,-64.67870768049613
\end{filecontents*}
\begin{filecontents*}{ArbitraryPhaseUncontrolledMag_s11_prototype.csv}
freq,s11_dB
0.01,-15.84224832175662
1,-1.478814217873018e-06
\end{filecontents*}
\begin{filecontents*}{ArbitraryPhaseUncontrolledMag_gd_prototype.csv}
freq,group_delay
0.01495,2.587062551091017
1,0.05680967942229484
\end{filecontents*}
\begin{document}
\begin{tikzpicture}
\pgfplotsset{mysqstyle/.style={x unit=Hz,
xlabel={Frequency}},
myxstyle/.style={axis y line=none,
axis x line*=bottom,
grid=none,
xlabel=Frequency,
x unit=rad/s,
xmin=0,xmax=10,
ymin=0,ymax=0,
xtick distance=2,
xticklabel={\ifdim\tick pt=0pt $0$
\else\ifdim\tick pt=10pt $2\pi$
\else$\frac{\pgfmathprintnumber{\tick}\pi}{5}$\fi\fi},
height=1.3cm},
table/x={freq},
table/col sep=comma}
\begin{groupplot}[
group style={
group size=2 by 2,
horizontal sep=2cm,
vertical sep=0.7cm,
xlabels at=edge bottom,
ylabels at=edge left},
width=.4\textwidth,
scale only axis,
scaled x ticks=false,
change x base,
grid=major,
enlargelimits=true]
\nextgroupplot[ylabel=$S_{21}$,mysqstyle]
\addplot[blue] table[y=s21_dB]
{ArbitraryPhaseUncontrolledMag_s21_prototype.csv};
\addplot[red] table[y=s11_dB]
{ArbitraryPhaseUncontrolledMag_s11_prototype.csv};
\nextgroupplot[ylabel=$\tau_{g}$,mysqstyle]
\addplot[blue] table[y=group_delay]
{ArbitraryPhaseUncontrolledMag_gd_prototype.csv};
\nextgroupplot[myxstyle]
\nextgroupplot[myxstyle]
\end{groupplot}
\end{tikzpicture}
\end{document}