Define section title span in preamble for KOMA twocolumn scrbook

Question

I put multiple short sections together to a book. I want a two column layout, but a new section should always span both columns. The sections are generated from markdown files with pandoc.

I tried @xports approach with \multicol, but I do not want to edit each section title and would prefer to define the behavior in the preamble.

\documentclass[twocolumn=true]{scrbook}
\usepackage{lipsum}
\begin{document}
\chapter{Chapter 1}
\section{Section 1}
\lipsum[1-2]
\section{Section 2}
\lipsum[3-4]
\section{Section 3}
\lipsum[1-4]
\chapter{Chapter 2}
\section{Section 1}
\lipsum[1-2]
\section{Section 2}
\lipsum[3-4]
\section{Section 3}
\lipsum[1-5]
\end{document}

Jasper Habicht · Answer 1 · 2021-04-08T06:00:04.533

3

Welcome to TeX.SX! You could make use of the cuted package like in the following example. It may be possible, I think, that LaTeX doesn't always prevent page breaks between the section title and the following paragraph. Maybe some adjustment is needed.

\documentclass[twocolumn=true]{scrbook}
\usepackage{lipsum, cuted}
\renewcommand{\sectionlinesformat}[4]{%
\begin{strip}\thesection\autodot\enskip #4\end{strip}%
}
\begin{document}
\chapter{Chapter 1}
\section{Section 1}
\lipsum[1-3]
\section{Section 2}
\lipsum[3-6]
\section{Section 3}
\lipsum[1-4]
\chapter{Chapter 2}
\section{Section 1}
\lipsum[1-2]
\section{Section 2}
\lipsum[3-4]
\section{Section 3}
\lipsum[1-5]
\end{document}

First page of the output:

Edit: If you don't want to use the same styling for subsection headings, you can use the following to apply the above settings only to sections. I also changed the code so that the starred version of section title won't get a section number:

\documentclass[twocolumn=true]{scrbook}
\usepackage{lipsum, cuted}
\makeatletter
\renewcommand{\sectionlinesformat}[4]{%
\Ifstr{#1}{section}{%
\begin{strip}@hangfrom{\hskip #2#3}{#4}\end{strip}%
}{%
@hangfrom{\hskip #2#3}{#4}%
}%
}
\makeatother
\begin{document}
\chapter{Chapter 2}
\section{Section 1}
\lipsum[1-2]
\subsection{Subsection 1}
\lipsum[2]
\section{Section 2}
\lipsum[3-4]
\section{Section 3}
\lipsum[1-5]
\end{document}

The first page of the output renders like this:

edited Apr 08 '21 at 06:00

answered Apr 07 '21 at 17:28

Jasper Habicht

48,848

Your redefinition of \sectionlinesformat gives unexpected results for e.g. subsection headings or unnumbered sections headings, because the section number would be used for them, too. Additionally environment strip would be used for e.g. subsections, too. – esdd Apr 07 '21 at 20:10
@esdd You are right. See my edit. You then need to restrict the re-formatting so that it only applies to section headers. I am not sure why the spacing sometimes seems to be a bit off, though. – Jasper Habicht Apr 07 '21 at 21:24
Why you do not use the original definition for the section level in environment strip, i.e. \begin{strip}\@hangfrom{\hskip #2#3}{#4}\end{strip}? – esdd Apr 07 '21 at 22:00
3

You can load package needspace. And you could use the hooks for the headings provided by the class scrbook: \AddtoDoHook{heading/begingroup/section}{\startonecolumn} and \AddtoDoHook{heading/endgroup/section}{\stoponecolumn} with \newcommand*{\startonecolumn}[1]{\begin{strip}\needspace{4\baselineskip}} and \newcommand*{\stoponecolumn}[1]{\end{strip}}. – esdd Apr 07 '21 at 22:08
@esdd|s solution works great and is really beautiful! I have some issues with spacing and column breaking, but I assume this is due to my short sections with lots of lists. – orangerkater Apr 08 '21 at 06:45
Any ideas, how to prevent section headings separating from the section? – orangerkater Apr 08 '21 at 06:50
1

I think @esdd's solution is indeed great and they should post it as an answer! But @orangerkater is right: somehow, neither \nopagebreak nor \needspace can really prevent the headings from being seperated in certain situations. – Jasper Habicht Apr 08 '21 at 07:01

Peter Wilson · Answer 2 · 2021-04-07T17:35:45.607

Here is a method that will work for your MWE.

% sectionprob.tex  SE 591865
%\documentclass[twocolumn=true]{scrbook}
\documentclass{scrbook}
\usepackage{multicol}
\usepackage{lipsum}
% \section not in multicolumn
\let\savesection\section
\renewcommand{\section}[1]{%
  \end{multicols}
  \savesection{#1}
  \begin{multicols}{2}}
% \chapter not in multicolumn
\let\savechapter\chapter
\renewcommand{\chapter}[1]{%
  \end{multicols}
  \savechapter{#1}
  \begin{multicols}{2}}
\begin{document}
\begin{multicols}{2}  % start 2 columns
\chapter{Chapter 1}
\section{Section 1}
\lipsum[1-2]
\section{Section 2}
\lipsum[3-4]
\section{Section 3}
\lipsum[1-4]
\chapter{Chapter 2}
\section{Section 1}
\lipsum[1-2]
\section{Section 2}
\lipsum[3-4]
\section{Section 3}
\lipsum[1-5]
\end{multicols} % end 2 columns
\end{document}

Strangely to me regular \chapter in a 2 column multicolumn gets set above the second column.

Your redefinition of \chapter and \section breaks, if their starred version or the optional argument would be used. \tableofcontents can not be used. — esdd, Apr 07 '21 at 20:14
@esdd My solution works for the given MWE. I admit that It will not work for starred versions or those with optional parameters but the OP gave no indication that they might be used. I felt that I had spent enough time on this without going into all possible (but possibly unused) versions. --- GOM — Peter Wilson, Apr 09 '21 at 18:00

score 2 · Accepted Answer · answered Apr 09 '21 at 09:54

As proposed in a comment by @esdd I used a hook for the headings with cuted and needspace:

\documentclass[twocolumn=true]{scrbook}
\usepackage{lipsum}
\usepackage{cuted, needspace}
\newcommand{\startonecolumn}[1]{\begin{strip}\needspace{4\baselineskip}}
\newcommand{\stoponecolumn}[1]{\end{strip}}
\AddtoDoHook{heading/begingroup/section}{\startonecolumn}
\AddtoDoHook{heading/endgroup/section}{\stoponecolumn}
% \AddtoDoHook{heading/begingroup/subsection}{\startonecolumn}
% \AddtoDoHook{heading/endgroup/subsection}{\stoponecolumn}
\begin{document}
\chapter{Chapter 1}
\section{Section 1}
\lipsum[1]
\subsection{Subsection 1}
\lipsum[2]
\section{Section 2}
\lipsum[3-4]
\section{Section 3}
\lipsum[1-4]
\chapter{Chapter 2}
\section{Section 1}
\lipsum[1-2]
\section{Section 2}
\lipsum[3-4]
\section{Section 3}
\lipsum[1-5]
\end{document}

I also added the hooks for spanning subsections (commented out above).

Define section title span in preamble for KOMA twocolumn scrbook

3 Answers3