带有辅助 y 轴的 pgfplots 图表的宽度与没有辅助 y 轴的图表的宽度不同

Question

在 pgfplots 中，如何使具有辅助 y 轴的图形与没有辅助 y 轴的图形宽度相同？我已经指定了相同的宽度，但在输出中显然它们的宽度不同。

\documentclass{article}
\usepackage{pgfplots}
\begin{document}

% 1st graph
    \begin{tikzpicture}
    \centering
    \pgfplotsset{set layers}
    \begin{axis}\[
        width = 0.8\textwidth,
        scale only axis,
        axis y line* = left,
        title = {1st Graph},
        \]
    \end{axis}
    \begin{axis}\[
        width = 0.8\textwidth,
        scale only axis,
        axis y line* = right,
        axis x line = none,
        \]
    \end{axis}
    \end{tikzpicture}
    
    % 2nd graph
    \begin{tikzpicture}
    \centering
    \begin{axis}\[
        width = 0.8\textwidth,
        title = {2nd Graph},
        \]
    \end{axis}
    \end{tikzpicture}
    
    \end{document}

Answer 1

\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
width=0.8\textwidth,
scale only axis,
axis y line*=left,
title={1st Graph},
]
\end{axis}
\begin{axis}[
width=0.8\textwidth,
scale only axis,
axis y line*=right,
axis x line=none,
]
\end{axis}
\end{tikzpicture}

\begin{tikzpicture}
\begin{axis}[
width=0.8\textwidth,
scale only axis,
title={2nd Graph},
]
\end{axis}
\end{tikzpicture}
\end{document}