decrease table wrapped text spacing

Question

I was working on some tables and thought about having the text for the leftmost index wrapped on two lines.

However, I wish to have the linespacing for cells with text wrapped – Connected components and Estimated sequence length – to be smaller than the overall setting for the document just to make clear we are still within the same cell. See below for an example:

and related code

\documentclass[12pt]{report}


\usepackage[letterpaper,margin=1in]{geometry}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{subcaption}
\usepackage{caption}
\usepackage{amsmath}
\usepackage{xcolor}
\usepackage{float}

\usepackage{longtable,booktabs,siunitx}
\renewcommand{\baselinestretch}{1.5}

\begin{document}

\begin{longtable}{@{\extracolsep{\fill}} p{0.20\linewidth} *{4}{S[table-format=2.2]}}
\caption[\textbf{}]{\textbf{} } 
\label{table:graphs} \\
\toprule
& \multicolumn{4}{c}{\textbf{GRAPH}} \\
\cmidrule{2-5}
& \multicolumn{2}{c}{\texttt{minigraph-CACTUS}}  
& \multicolumn{2}{c}{\texttt{PGGB}} \\
\cmidrule{2-3} \cmidrule{4-5}

& {\textit{GRCh38-only}} & {\textit{CHM13}} & {\textit{GRCh38-only}} & {\textit{CHM13}} \\
\cmidrule{2-5}

\centering\textbf{Node Count} &  \\
\centering\textbf{Edge Count} &  \\
\centering\textbf{Total length} &  \\
\centering\textbf{Dead ends} &  \\
\centering\textbf{Connected components} &  \\
\centering\textbf{Median depth} &  \\
\centering\textbf{Estimated sequence length} &  \\
\midrule[\heavyrulewidth]
\end{longtable}

\end{document}

Now, I tried some options but they all screwed up the between-cell spacing... is there a way to do so locally just for those two cells preserving the overall document formatting? Thanks in advance!

Answer 1

The cells display the required line space since you set \renewcommand{\baselinestretch}{1.5} (I hope you didn't do that only for the table, otherwise you should better use \renewcommand{\arraystretch}{1.5}).

You need to restore the \baselinestretch. A \selectfont command is needed to make if effective:

\renewcommand{\baselinestretch}{1}\selectfont

For example, define a new command:

\newcommand{\smallerbaseline}{\renewcommand{\baselinestretch}{1}\selectfont}

and use it where needed

\smallerbaseline\textbf{Connected components}

For the tabular, you can include it in its definition:

\begin{longtable}{
  @{\extracolsep{\fill}}
  >{\smallerbaseline} p{0.20\linewidth}
  *{4}{S[table-format=2.2]}
}

Full example (I also moved the \centering and bod face setting of the first column into the tabular definition).

\documentclass[12pt]{report}


\usepackage[letterpaper,margin=1in]{geometry}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{subcaption}
\usepackage{caption}
\usepackage{amsmath}
\usepackage{xcolor}
\usepackage{float}

\usepackage{longtable,booktabs,siunitx}
\renewcommand{\baselinestretch}{1.5}

\newcommand{\smallerbaseline}{\renewcommand{\baselinestretch}{1}\selectfont}

\begin{document}

\begin{longtable}{%
    @{\extracolsep{\fill}}
    >{\centering\arraybackslash\smallerbaseline\bfseries} p{0.20\linewidth}
    *{4}{S[table-format=2.2]}
}
\caption[\textbf{}]{\textbf{} }
\label{table:graphs} \\
\toprule
& \multicolumn{4}{c}{\textbf{GRAPH}} \\
\cmidrule{2-5}
& \multicolumn{2}{c}{\texttt{minigraph-CACTUS}}
& \multicolumn{2}{c}{\texttt{PGGB}} \\
\cmidrule{2-3} \cmidrule{4-5}

& {\textit{GRCh38-only}} & {\textit{CHM13}} & {\textit{GRCh38-only}} & {\textit{CHM13}} \\
\cmidrule{2-5}
Node Count &  \\
Edge Count &  \\
Total length &  \\
Dead ends &  \\
Connected components &  \\
Median depth &  \\
Estimated sequence length &  \\
\midrule[\heavyrulewidth]
\end{longtable}

\end{document}

An alternative, with \arraystretch (add \smallerbaseline after \begingroup if you really need a larger baseline in your document):

\begingroup
\renewcommand{\arraystretch}{1.5}
\begin{longtable}{%
    @{\extracolsep{\fill}}
    >{\centering\arraybackslash\bfseries} p{0.20\linewidth}
    *{4}{S[table-format=2.2]}
}
\caption[\textbf{}]{\textbf{} }
\label{table:graphs} \\
\toprule
& \multicolumn{4}{c}{\textbf{GRAPH}} \\
\cmidrule{2-5}
& \multicolumn{2}{c}{\texttt{minigraph-CACTUS}}
& \multicolumn{2}{c}{\texttt{PGGB}} \\
\cmidrule{2-3} \cmidrule{4-5}

& {\textit{GRCh38-only}} & {\textit{CHM13}} & {\textit{GRCh38-only}} & {\textit{CHM13}} \\
\cmidrule{2-5}
Node Count &  \\
Edge Count &  \\
Total length &  \\
Dead ends &  \\
Connected components &  \\
Median depth &  \\
Estimated sequence length &  \\
\midrule[\heavyrulewidth]
\end{longtable}
\endgroup

Answer 2

If you are going to change \baselinestretch, it is probably better to use setspace so you have ready-made means to alter it and some of the side-effects are mitigated for you. However, you should know that the standard classes can misbehave when the value is altered globally because lots of things depend on the value of \baselinestretch in ways which may not be obvious. setspace improves things a bit, but only a bit.

I'd actually use a modified version of the singlespace environment in the tabular cells to avoid excessive spacing between the rows. In the code below, I call this environment singlespaced and apply it to the first column (together with \centering and \bfseries) using the > and < facilities of the array package, which you are already implicitly loading.

\documentclass[12pt,letterpaper]{report}
\usepackage[margin=1in]{geometry}
% \usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{subcaption}
% \usepackage{caption}
\usepackage{amsmath}
\usepackage{xcolor}
\usepackage{float}

\usepackage{longtable,booktabs,siunitx}
\usepackage{setspace}
\makeatletter
\newenvironment{singlespaced}{%
  \vskip \baselineskip
  \setstretch {\setspace@singlespace}%
  \vskip -2\baselineskip
}{%
  \par
}
\makeatother
\setstretch{1.5}

\begin{document}

  \begin{longtable}{@{\extracolsep{\fill}} >{\bfseries\centering\singlespaced} p{0.20\linewidth} <{\endsinglespaced} *{4}{S[table-format=2.2]}}
  \caption[\textbf{}]{\textbf{} } 
  \label{table:graphs} \\
  \toprule
  & \multicolumn{4}{c}{\textbf{GRAPH}} \\
  \cmidrule{2-5}
  & \multicolumn{2}{c}{\texttt{minigraph-CACTUS}}  
  & \multicolumn{2}{c}{\texttt{PGGB}} \\
  \cmidrule{2-3} \cmidrule{4-5}
  
  & {\textit{GRCh38-only}} & {\textit{CHM13}} & {\textit{GRCh38-only}} & {\textit{CHM13}} \\
  \cmidrule{2-5}
  
  Node Count &  \\
  Edge Count &  \\
  Total length &  \\
  Dead ends &  \\
  Connected components &  \\
  Median depth &  \\
  Estimated sequence length &  \\
  \bottomrule
\end{longtable}

\end{document}

[No image due to Okular/KDE bug which renders them so ugly you would scream in horror if not omitted.]