我想在第一行的第二列和第三列下放置一行。单元格的内容应为“ET in sec.”，第二个单元格的内容应为“Memory in MB”。第三列也一样。可以吗？因为每个单元格的第一个值是用连字符分隔的已用时间，第二个值是 Memory in MB。
\documentclass{article}
\begin{document}
\begin{center}
\begin{tabular}{ |c|c|c|c| }
\hline
Random AST depth & Static schedule evaluation & Demand evaluation ET in sec. \\ \hline
& ET in sec. | Memory in MB & ET in sec. | Memory in MB \\ \hline
1 & 0.009 - 2.971 & 0.091 - 5.536 \\ \hline
2 & 0.003 - 2.921 & 0.009 - 3.178 \\ \hline
3 & 0.005 - 3.646 & 0.009 - 4.037 \\ \hline
4 & 0.019 - 7.872 & 0.019 - 9.548 \\ \hline
5 & 0.097 - 13.091 & 0.123 - 21.288 \\ \hline
6 & 0.044 - 46.332 & 0.053 - 86.475 \\ \hline
7 & 0.064 - 57.778 & 0.122 - 112.154 \\ \hline
8 & 0.501 - 155.338 & 0.761 - 453.930 \\ \hline
9 & 4.029 - 198.215 & 2.276 - 866.845 \\ \hline
10 & 7.439 - 1346.093 & 9.757 - 1652.442 \\ \hline
11 & 30.57 - 1368.750 & 43.098 - 1915.167 \\
\hline
\end{tabular}
\end{center}
\end{document}
答案1
你没有给出最终的显示效果，我不清楚你想要什么效果，我按照我的猜测帮你实现了一个，你看看是否符合你的要求。
\documentclass{article}
\usepackage[margin=3cm]{geometry}
\usepackage{xcolor}
\usepackage{tabularray}
\UseTblrLibrary{siunitx}
\begin{document}
\begin{table}
\caption{title}
\begin{tblr}
{
colspec = {X[c,m]X[c,m]X[c,m]X[c,m]X[c,m]},
cell{1}{2,4} = {c=2}{},
cell{1}{1} = {r=2}{},
hlines,
vlines,
}
Random AST depth & Static schedule evaluation & & Demand evaluation ET in sec. & \\
& ET in sec. & Memory in MB & ET in sec. & Memory in MB \\
1 & 0.009 & 2.971 & 0.091 & 5.536 \\
2 & 0.003 & 2.921 & 0.009 & 3.178 \\
3 & 0.005 & 3.646 & 0.009 & 4.037 \\
4 & 0.019 & 7.872 & 0.019 & 9.548 \\
5 & 0.097 & 13.091 & 0.123 & 21.288 \\
6 & 0.044 & 46.332 & 0.053 & 86.475 \\
7 & 0.064 & 57.778 & 0.122 & 112.154 \\
8 & 0.501 & 155.338 & 0.761 & 453.930 \\
9 & 4.029 & 198.215 & 2.276 & 866.845 \\
10 & 7.439 & 1346.093 & 9.757 & 1652.442 \\
11 & 30.57 & 1368.750 & 43.098 & 1915.167 \\
\end{tblr}
\end{table}
\begin{table}
\caption{title}
\begin{tblr}
{
colspec = {Q[co=1,c,m]*{4}{Q[co=1,si={table-format=4.3},c,m]}},
cell{1}{2,4} = {c=2}{},
cell{1}{1} = {r=2}{},
hline{1,Z} = {wd=.08em},
hline{2} = {2-Z}{wd=.05em},
hline{3} = {wd=.05em},
row{odd[3-Z]} = {bg=gray9!50},
column{1} = {guard},
row{1-2} = {guard},
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Random AST depth & Static schedule evaluation & & Demand evaluation ET in sec. & \\
& ET in sec. & Memory in MB & ET in sec. & Memory in MB \\
1 & 0.009 & 2.971 & 0.091 & 5.536 \\
2 & 0.003 & 2.921 & 0.009 & 3.178 \\
3 & 0.005 & 3.646 & 0.009 & 4.037 \\
4 & 0.019 & 7.872 & 0.019 & 9.548 \\
5 & 0.097 & 13.091 & 0.123 & 21.288 \\
6 & 0.044 & 46.332 & 0.053 & 86.475 \\
7 & 0.064 & 57.778 & 0.122 & 112.154 \\
8 & 0.501 & 155.338 & 0.761 & 453.930 \\
9 & 4.029 & 198.215 & 2.276 & 866.845 \\
10 & 7.439 & 1346.093 & 9.757 & 1652.442 \\
11 & 30.57 & 1368.750 & 43.098 & 1915.167 \\
\end{tblr}
\end{table}
\end{document}
答案2
连字符会分散注意力，并妨碍数字对齐。这里有两个建议；在这两个建议中，都省略了垂直线，因为它们无用且不利于阅读。
\documentclass{article}
\usepackage{booktabs,siunitx}
\begin{document}
\begin{center}
\begin{tabular}{
@{}
c
S[table-format=2.3]
@{\hspace{3\tabcolsep}}
S[table-format=4.3]
S[table-format=2.3]
S[table-format=4.3]
@{}
}
\toprule
\smash{\begin{tabular}[t]{@{}c@{}} Random \\ AST depth \end{tabular}} &
\multicolumn{2}{c}{Static schedule evaluation} &
\multicolumn{2}{c@{}}{Demand evaluation} \\
\cmidrule(lr){2-3} \cmidrule(l){4-5}
& {ET (s)} & {Memory (MB)} & {ET (s)} & {Memory (MB)} \\
\midrule
1 & 0.009 & 2.971 & 0.091 & 5.536 \\
2 & 0.003 & 2.921 & 0.009 & 3.178 \\
3 & 0.005 & 3.646 & 0.009 & 4.037 \\
4 & 0.019 & 7.872 & 0.019 & 9.548 \\
5 & 0.097 & 13.091 & 0.123 & 21.288 \\
6 & 0.044 & 46.332 & 0.053 & 86.475 \\
7 & 0.064 & 57.778 & 0.122 & 112.154 \\
8 & 0.501 & 155.338 & 0.761 & 453.930 \\
9 & 4.029 & 198.215 & 2.276 & 866.845 \\
10 & 7.439 & 1346.093 & 9.757 & 1652.442 \\
11 & 30.57 & 1368.750 & 43.098 & 1915.167 \\
\bottomrule
\end{tabular}
\end{center}
\begin{center}
\begin{tabular}{
@{}
c
S[table-format=2.3]
S[table-format=4.3]
S[table-format=2.3]
S[table-format=4.3]
@{}
}
\toprule
\smash{\begin{tabular}[t]{@{}c@{}} Random \\ AST \\ depth \end{tabular}} &
\multicolumn{4}{c@{}}{Evaluation} \\
\cmidrule(l){2-5}
& \multicolumn{2}{c}{Static schedule} &
\multicolumn{2}{c@{}}{Demand} \\
\cmidrule(lr){2-3} \cmidrule(l){4-5}
& {ET} & {Memory} & {ET} & {Memory} \\
\midrule
1 & 0.009 & 2.971 & 0.091 & 5.536 \\
2 & 0.003 & 2.921 & 0.009 & 3.178 \\
3 & 0.005 & 3.646 & 0.009 & 4.037 \\
4 & 0.019 & 7.872 & 0.019 & 9.548 \\
5 & 0.097 & 13.091 & 0.123 & 21.288 \\
6 & 0.044 & 46.332 & 0.053 & 86.475 \\
7 & 0.064 & 57.778 & 0.122 & 112.154 \\
8 & 0.501 & 155.338 & 0.761 & 453.930 \\
9 & 4.029 & 198.215 & 2.276 & 866.845 \\
10 & 7.439 & 1346.093 & 9.757 & 1652.442 \\
11 & 30.57 & 1368.750 & 43.098 & 1915.167 \\
\midrule[\heavyrulewidth]
\multicolumn{5}{@{}l@{}}{ET in seconds, Memory in MB}
\end{tabular}
\end{center}
\end{document}
