numberingsectioning
I'm using the book class. My chapters are numbered with 1,2,3,… I have already managed to have my sections be numbered with only 1,2,3,… (they reset upon a new chapter).
How can I number my subsections with A,B,C,… such that they reset to A upon new sections/chapters?
If you change the document class from article to book or report, your document works without error. The code in your question uses the \chapter command which is undefined in the article class. Try:
\documentclass{book}
\setcounter{secnumdepth}{-1}
\begin{document}
\tableofcontents
\chapter{mwe}
\section{unnumbered subsections}
\subsection{unnumbered}
\section{roman numbered subsections}
\setcounter{secnumdepth}{2}
\renewcommand{\thesubsection}{\textnormal{\roman{subsection}}.}
\subsection{roman one}
\subsection{roman two}
\setcounter{secnumdepth}{-1}
\chapter{Second chapter}
\section{unnumbered subsections}
\subsection{unnumbered}
\end{document}
Sometimes it's good to use \addtocounter instead of \setcounter, so you could raise or lower the numbering level without using the absolute value.
Also, as you can see, I used the counter value -1 for not numbering chapters, instead of 0.
In general, I think it's a bit inconsistent to change the numbering depth within a document.
Package hyperref needs the counter values to generate unique anchor names. But there are counter values that are not unique. For example, you have several sections with number 1.
Because of this, hyperref has introduced \theH<counter> and prefers it over \the<counter> for use in anchor names. \the<counter> might contain weird or duplicate values. As long as \theH<counter> expands to a simple unique string, hyperref is happy.
The following example provides unique definitions for \theHsection:
\documentclass{report}
\usepackage{hyperref}
\usepackage{bookmark}
\bookmarksetup{
numbered,
open
}
\renewcommand*{\thesection}{\arabic{section}}
\begin{document}
\tableofcontents
\chapter{First numbered chapter}
\section{AB}
\section{BC}
\section{DE}
\chapter*{First unnumbered chapter}
\addcontentsline{toc}{chapter}{First unnumbered chapter}
\setcounter{section}{0}
\renewcommand*{\theHsection}{chX.\the\value{section}}
\section{FG}
\section{HI}
\section{IJ}
\chapter*{Second unnumbered chapter}
\addcontentsline{toc}{chapter}{Second unnumbered chapter}
\setcounter{section}{0}
\renewcommand*{\theHsection}{chY.\the\value{section}}
\section{KL}
\section{MN}
\section{NO}
\renewcommand*{\theHsection}{\theHchapter.\the\value{section}}
\chapter{Last numbered chapter}
\section{PQ}
\section{RS}
\section{TU}
\end{document}
Best Answer
Since by default the counter for subsections will reset every new section, all you have to do is to redefine the
\thesubsectioncommand controlling the representation of thesubsectioncounter:A little example:
The above solution won't work as expected if you use a
\subsectionimmediately after a\chaptercommand (without issuing a\sectionin between); to cope for this situation, you can use thechngcntrpackage to make the subsection counter reset also when the chapter counter is incremented: