我试图让这张表适合我的研究论文的一列，我尝试使用\setlength{\tabcolsep}{1pt}命令，但没有成功。
\begin{table}[ht]
\setlength{\tabcolsep}{1pt}
\centering
\vspace{-0.5cm}
\begin{tabular}{|c||c|c|c|c|c|c|}
\hline
\multicolumn{7}{|c|}{Precision} \\
\hline
Classifier & Text-specific (1) & N-grams (2) & Post-specific (3) & 1 \& 2 & 1 \& 3 & All\\
\hline
\perceptron & 0.78 & 0.82 & 0.24 & 0.81 & 0.77 & 0.83\\
\decisiontree & 0.65 & 0.79 & 0.56 & 0.75 & 0.65 & 0.73\\
\svm & 0.74 & 0.72 & 0.50 & 0.80 & 0.73 & 0.85\\
\isolationforest & 0.54 & 0.51 & 0.52 & 0.53 & 0.54 & 0.53\\
\hline
\end{tabular}
\caption{Precision results of the classifiers for different feature subsets. 1 \& 2 is the combination of text-specific features
\& n-grams. 1 \& 3 is the combination of text- and post-specific
features.}
\label{table:classifier_feature_subsets_prec}
\end{table}
序言部分：
\def\year{2018}\relax
%File: formatting-instruction.tex
\documentclass[letterpaper]{article} %DO NOT CHANGE THIS
\usepackage{aaai18} %Required
\usepackage{times} %Required
\usepackage{helvet} %Required
\usepackage{courier} %Required
\usepackage{url} %Required
\usepackage{graphicx} %Required
\usepackage[usenames,dvipsnames,table,xcdraw]{xcolor}
\usepackage{todonotes}
\usepackage{hyperref}
\usepackage{csquotes}
\usepackage{xspace}
\usepackage{pgfplots}
\usepackage{chapterbib}
\newcommand{\decisiontree}{Decision Tree\xspace}
\newcommand{\decisiontrees}{Decision Tree\xspace}
\newcommand{\svm}{One-Class~SVM\xspace}
\newcommand{\svms}{One-Class~SVMs\xspace}
\newcommand{\perceptron}{Perceptron\xspace}
\newcommand{\perceptrons}{Perceptrons\xspace}
\newcommand{\isolationforest}{Isolation Forest\xspace}
\newcommand{\isolationforests}{Isolation Forests\xspace}
\frenchspacing %Required
\setlength{\pdfpagewidth}{8.5in} %Required
\setlength{\pdfpageheight}{11in} %Required
%PDF Info Is Required:
\pdfinfo{
答案1
替代 ...
使用threepartable和tabular*：
\documentclass[letterpaper, twocolumn]{article}
\usepackage[margin=1in]{geometry}
\usepackage{booktabs,threeparttable}
\usepackage{lipsum}
\begin{document}
\lipsum[11]
\begin{threeparttable}[htb]
\caption{Precision results of the classifiers for different feature subsets.}
\label{table:classifier_feature_subsets_prec}
\small
\setlength\tabcolsep{0pt}
\begin{tabular*}{\linewidth}{@{\extracolsep{\fill}} l cc cc cc @{}}
\toprule
& \multicolumn{6}{c}{Precision} \\
\cmidrule{2-7}
Classifier & (1)\tnote{a}
& (2)\tnote{b}
& (3)\tnote{c}
& (1\&2)\tnote{d}
& (1\&3)\tnote{e}
& All\\
\midrule
Perceptron & 0.78 & 0.82 & 0.24 & 0.81 & 0.77 & 0.83\\
Decision Tree & 0.65 & 0.79 & 0.56 & 0.75 & 0.65 & 0.73\\
One-Class~SVM & 0.74 & 0.72 & 0.50 & 0.80 & 0.73 & 0.85\\
Isolation Forest & 0.54 & 0.51 & 0.52 & 0.53 & 0.54 & 0.53\\
\bottomrule
\end{tabular*}
\begin{tablenotes}[para,flushleft,small]
\item[a] 1: Text-specific,
\item[b] 2: N-grams,
\item[c] 3: Post-specific,
\item[d] (1\&2): combination of Text-specific and N-grams,
\item[e] (1\&3): combination of Text-specific and Post-specific
\end{tablenotes}
\end{threeparttable}
\end{document}
答案2
以下是两种可能的解决方案。
第一种是采用基本布局（看上去相当杂乱，有很多垂直线），然后切换到环境
tabularx以便内容可以适应。请注意，仍然需要切换到环境\footnotesize并且几乎不使用任何列间空白。第二种解决方案力求使表格看起来更开放，方法是删除所有垂直线，并使用间距适当的水平线代替
\hline。这种方法的一个（有益的）副产品是可以使用\small代替\footnotesize并使用更多的列间空白。请注意，我还简化了标题，方法是将表格图例中真正的一部分移到表格本身的正下方。
\documentclass[letterpaper]{article}
\usepackage{aaai18} % from http://www.aaai.org/Conferences/AAAI/2018/aaai18call.php
\usepackage{times,helvet,courier,xcolor}
\usepackage{tabularx,ragged2e,booktabs,caption}
\newcolumntype{C}{>{\Centering\arraybackslash}X} %
\frenchspacing
\begin{document}
\begin{table}[h]
\footnotesize
\setlength{\tabcolsep}{1pt} % hardly any whitespace between columns!
\setlength\extrarowheight{1pt}
\textcolor{red}{Table with vertical lines}
\begin{tabularx}{\columnwidth}{|l||*{6}{C|}}
\hline
\multicolumn{7}{|c|}{Precision} \\
\hline
Classifier & Text-specific (1)
& N-grams (2) & Post-specific (3)
& 1 \& 2 & 1 \& 3 & All\\
\hline
Perceptron & 0.78 & 0.82 & 0.24 & 0.81 & 0.77 & 0.83\\
Decision Tree & 0.65 & 0.79 & 0.56 & 0.75 & 0.65 & 0.73\\
One-Class SVM & 0.74 & 0.72 & 0.50 & 0.80 & 0.73 & 0.85\\
Isolation Forest & 0.54 & 0.51 & 0.52 & 0.53 & 0.54 & 0.53\\
\hline
\end{tabularx}
\caption{Precision results of the classifiers for different feature subsets.
1 \& 2 is the combination of text-specific features and n-grams.
1 \& 3 is the combination of text- and post-specific features.}
\label{table:classifier_feature_subsets_prec}
\end{table}
\begin{table}[h]
\small % "\footnotesize" not needed here
\captionsetup{size=small}
\textcolor{red}{No vertical lines; well-spaced horizontal lines; simplified caption}
\setlength{\tabcolsep}{2pt} % a bit more whitespace
\begin{tabularx}{\columnwidth}{@{} l *{5}{C} c @{}}
\toprule
Classifier & \multicolumn{6}{c@{}}{Precision} \\
\cmidrule(l){2-7}
& Text-specific (1) & N-grams (2) & Post-specific (3)
& 1 \& 2 & 1 \& 3 & All\\
\midrule
Perceptron & 0.78 & 0.82 & 0.24 & 0.81 & 0.77 & 0.83\\
Decision Tree & 0.65 & 0.79 & 0.56 & 0.75 & 0.65 & 0.73\\
One-Class SVM & 0.74 & 0.72 & 0.50 & 0.80 & 0.73 & 0.85\\
Isolation Forest & 0.54 & 0.51 & 0.52 & 0.53 & 0.54 & 0.53\\
\bottomrule
\end{tabularx}
\smallskip
1 \& 2 is the combination of text-specific features and n-grams.
1 \& 3 is the combination of text- and post-specific features.
\caption{Precision results of classifiers for various feature subsets.}
\label{table:new}
\end{table}
\end{document}