Beginning a New Chapter Not Necessarily on a New Page

Question

Consider the code

\documentclass[openany]{book}
\usepackage{lipsum}
\usepackage{pgfpages}
\pgfpagesuselayout{2 on 1}
\usepackage{xcolor}
\begin{document}
\thispagestyle{empty}
\Large
\chapter{\textcolor{red}{1}}
\lipsum[13]
\chapter{\textcolor{red}{2}}
\lipsum[19]
\chapter{\textcolor{red}{3}}
\lipsum[13]
\chapter{\textcolor{red}{4}}
\lipsum[19]
\end{document}

which produces the output:

Here, a new chapter always begins on a new page. I would change this.

QUESTION: How may I begin a new chapter on the same page (space permitting) that the previous chapter ended (i) on a selective basis (i.e., for only certain chapters); and (ii), on a global basis (i.e., for all chapters)?

Thank you.

For the book class, a new \chapter usually starts on a new page. Have you considered using \section with, say, the article class? That said, if you must, this should help: https://tex.stackexchange.com/questions/24066/start-new-chapter-on-same-page — Ingmar, Oct 26 '21 at 07:03

score 3 · Accepted Answer · answered Oct 26 '21 at 07:09

The following hack works in your case:

\usepackage{etoolbox}
\patchcmd{\chapter}{\clearpage}{\par}{}{}

The complete code is

\documentclass[openany]{book}
\usepackage{lipsum}
\usepackage{pgfpages}
\pgfpagesuselayout{2 on 1}
\usepackage{xcolor}
\usepackage{etoolbox}
\patchcmd{\chapter}{\clearpage}{\par}{}{}
\begin{document}
\thispagestyle{empty}
\Large
\chapter{\textcolor{red}{1}}
\lipsum[13]
\chapter{\textcolor{red}{2}}
\lipsum[19]
\chapter{\textcolor{red}{3}}
\lipsum[13]
\chapter{\textcolor{red}{4}}
\lipsum[19]
\end{document}

Beginning a New Chapter Not Necessarily on a New Page

1 Answers1