Memoir manual: “The numbering of parts has no effect on the numbering of \chapters.”

Question

I am writing my PhD using memoir class. I have 5 parts, divided into chapters. But before the first chapter of each part, I have an introduction to what the following chapters are about. Here's an example:

\documentclass{memoir}

\begin{document}

\tableofcontents

\part{First Part}

\section{An introduction to First Part}

\chapter{First chapter of First Part}

\section{First section of First chapter}

\chapter{Second chapter of First Part}

\section{First section of Second Chapter}

\section{Second section of Second Chapter}

\part{Second Part}      

\section{An introduction to Second Part}

\chapter{First chapter of Second Part}

\section{First section of First chapter}

\end{document}

The problem is that, until the first chapter of a new part is created, the headers are still related to the previous chapter and previous section, which is not what I intended.

Any ideas of how to solve this?

Answer 1

This is the behaviour of the standard classes.

If I understand your structure, the parts introductions are not part of any chapter, so maybe you shouldn't use \section title. If you want a title anyway, you may use non-numbered section: \section*

\documentclass{memoir}

\begin{document}

\tableofcontents

\part{First Part}

\section*{An introduction to First Part}

\chapter{First chapter of First Part}

\section{First section of First chapter}

\chapter{Second chapter of First Part}

\section{First section of Second Chapter}

\section{Second section of Second Chapter}

\part{Second Part}      

\section*{An introduction to Second Part}

\chapter{First chapter of Second Part}

\section{First section of First chapter}

\end{document}

Answer 2

Memoir uses a continuous pagestyle, with single-page interruptions (\thispagestyle{x}) at strategic element boundaries. This makes a good solution quite difficult for the structure you are using.

So I'd recommend making your introductions into first-class citizens by using \chapter rather than \section.

An alternative solution, a bit clunky in my opinion, is this:

In you preamble, define a new page style:

\copypagestyle{plainhead}{headings}
\makeevenhead{plainhead}{\thepage}{}{}
\makeoddhead{plainhead}{}{}{\thepage}

Then, for each part, add the necessary changes of page style:

\part{Another part...}
\pagestyle{plainhead}
\section{Introduction...}
... 
\clearforchapter
\pagestyle{headings}
\chapter{First chapter in new part...}

This doesn't solve any problems you may have with weird section numbering for the introduction sections, though. Turning the introductions into chapters in their own right is the best path, I believe.