如何定义表格中的子标题？

Question

我有下表：

\begin{table}[]
    \centering
    \begin{tabular}{SSSSSSSS}
    \toprule
    {Method} & {Number of windows} & {Size of windows} \\ \midrule
    {Window warping} & 45 & 2 seconds \\
    {Windowed magnitude warping} & 40 & 3 seconds \\ \bottomrule
    \end{tabular}
    \caption{Fixed hyperparameters}
    \label{tab:fixed_hyperparameters}
\end{table}

并显示下表：

我现在有不同的路线，我必须为这些路线定义值，并希望实现这样的目标（伪代码）：

\begin{table}[]
    \centering
    \begin{tabular}{SSSSSSSS}
    \toprule
    {Method} & {Number of windows} & {Size of windows} \\ \midrule
    {Route 1} \\ \midrule % should be aligned in the middle
    {Window warping} & 45 & 2 seconds \\
    {Windowed magnitude warping} & 40 & 3 seconds \\ \midrule

    {Route 2} \\ \midrule % should be aligned in the middle
    {Window warping} & 30 & 5 seconds \\
    {Windowed magnitude warping} & 25 & 2 seconds \\ \midrule

    {Route 3} \\ \midrule % should be aligned in the middle
    {Window warping} & 55 & 1 seconds \\
    {Windowed magnitude warping} & 40 & 5 seconds \\ \bottomrule
    \end{tabular}
    \caption{Fixed hyperparameters}
    \label{tab:fixed_hyperparameters}
\end{table}

Answer 1

为什么是S列？为什么只用三列就定义八列？第一列肯定不是S，因为它包含文本。我对第三列也有疑问：尺寸怎么能用秒来衡量？无论如何，你不应该每次都重复“秒”。

\documentclass{article}
\usepackage{siunitx,booktabs}

\begin{document}

\begin{table}[htp] % <--- NOT []
\centering

\begin{tabular}{
  @{}
  l
  S[table-format=2.0]
  S[table-format=1.0]
  @{}
}
\toprule
\multicolumn{1}{@{}c}{Method} & \multicolumn{2}{c@{}}{Windows} \\
\cmidrule{2-3}
& {Number} & {Size (seconds)} \\
\midrule

\multicolumn{1}{@{}c}{\itshape Route 1} \\
Window warping & 45 & 2 \\
Windowed magnitude warping & 40 & 3 \\
\midrule

\multicolumn{1}{@{}c}{\itshape Route 2} \\
Window warping & 30 & 5 \\
Windowed magnitude warping & 25 & 2 \\
\midrule

\multicolumn{1}{@{}c}{\itshape Route 3} \\ 
Window warping & 55 & 1 \\
Windowed magnitude warping & 40 & 5 \\
\bottomrule
\end{tabular}

\caption{Fixed hyperparameters}
\label{tab:fixed_hyperparameters}

\end{table}

\begin{table}[htp] % <--- NOT []
\centering

\begin{tabular}{
  @{}
  l
  S[table-format=2.0]
  S[table-format=1.0]
  @{}
}
\toprule
\multicolumn{1}{@{}c}{Method} & \multicolumn{2}{c@{}}{Windows} \\
\cmidrule{2-3}
& {Number} & {Size (seconds)} \\
\midrule

\qquad\itshape Route 1 \\
Window warping & 45 & 2 \\
Windowed magnitude warping & 40 & 3 \\
\midrule

\qquad\itshape Route 2 \\
Window warping & 30 & 5 \\
Windowed magnitude warping & 25 & 2 \\
\midrule

\qquad\itshape Route 3 \\
Window warping & 55 & 1 \\
Windowed magnitude warping & 40 & 5 \\
\bottomrule
\end{tabular}

\caption{Fixed hyperparameters}
\label{tab:fixed_hyperparameters-again}

\end{table}

\end{document}

我不会将“Route n”移到表格中间，而是将其放在第一列的中央或者稍微靠右一点，并使用不同的字体形状。