计算章节和附录

Question

在我的上次在不同文件之间交叉引用总数的经验，出现章节和附录计数的问题。

作为 MWE，我们可以使用给定的 MWE这里 做了一些修改。

有时像这样的简单命令 \setcounter{truechapters}{\value{totalchapters}-\value{chapter}}不起作用。

我猜测，原因在于错误地使用这些价值观。

问题是如何简单合理的方式在一个pdf中获取三个计数（总章节，附录和真实章节）？

请注意，我不能\zlabel像 Heiko 描述的那样使用这里

这是我的 MWE：

MyBook.tex：

\documentclass{memoir}
\usepackage{totcount}
\usepackage{assoccnt}

\newtotcounter{totalchapters}
\DeclareAssociatedCounters{chapter}{totalchapters} % Associate the driven counter `totalchapters` to the master counter `chapter`

\AtBeginDocument{
    %% register a counter on the basis of the last chapter in totcounter
    \regtotcounter{chapter}
}

\newcounter{truechapters}


\begin{document}

\chapter{A}
\chapter{B}
\appendix
\chapter{C}
\chapter{D}
\chapter{E}
\chapter{F}
\chapter{G}
\chapter{H}
\chapter{I}


There are \total{totalchapters} total chapters.


There are \total{chapter} appendix chapters.


%here we need to count the difference of two previous counters
%\setcounter{truechapters}{\value{totalchapters}-\value{chapter}} 


There are \thetruechapters \: true chapters.



\end{document}

MyBook.pdf 的截图如下：

Answer 1

您可以同时使用 LaTeX2e-kernel-macro\addtocounter和 eTeX-primitive\numexpr进行计算。

\documentclass{memoir}
\usepackage{totcount}
\usepackage{assoccnt}

\newtotcounter{totalchapters}
\DeclareAssociatedCounters{chapter}{totalchapters} % Associate the driven counter `totalchapters` to the master counter `chapter`

\AtBeginDocument{
    %% register a counter on the basis of the last chapter in totcounter
    \regtotcounter{chapter}
}
\newcounter{truechapters}

\begin{document}

\chapter{A}
\chapter{B}
\appendix
\chapter{C}
\chapter{D}
\chapter{E}
\chapter{F}
\chapter{G}
\chapter{H}
\chapter{I}

There are \total{totalchapters} total chapters.

There are \total{chapter} appendix chapters.

%here we need to count the difference of two previous counters
\setcounter{truechapters}{\value{totalchapters}}%
\addtocounter{truechapters}{-\value{chapter}}%

There are \thetruechapters \: true chapters.

\setcounter{truechapters}{\numexpr\value{totalchapters}-\value{chapter}\relax}%

There are \thetruechapters \: true chapters.

\end{document}

Answer 2

定义三个新的计数器，分别用于主要章节、附录和总数。

这里的技巧是添加代码来\appendix保存迄今为止的章节数truechapters并重置附录数量的计数器。

\documentclass{memoir}
\usepackage{etoolbox}
\usepackage{totcount,assoccnt}

\newcounter{truechapters}
\regtotcounter{truechapters}

\newcounter{totalchapters}
\newcounter{appendixchapters}
\DeclareAssociatedCounters{chapter}{totalchapters,appendixchapters}
\regtotcounter{totalchapters}
\regtotcounter{appendixchapters}

\preto\appendix{%
  % save the number of true chapters
  \setcounter{truechapters}{\value{chapter}}%
  % reset the number of chapters
  \setcounter{appendixchapters}{0}%
}


\begin{document}

\frontmatter

There are \total{totalchapters} total chapters.

There are \total{appendixchapters} appendix chapters.

There are \total{truechapters} true chapters.

\mainmatter

\chapter{A}
\chapter{B}
\appendix
\chapter{C}
\chapter{D}
\chapter{E}
\chapter{F}
\chapter{G}
\chapter{H}
\chapter{I}

\end{document}

Answer 3

egreg 解决方案的一个变体，这次使用最新的xassoccnt包（的后继者assoccnt），它对总计数器有部分支持。

\documentclass{memoir}
\usepackage{xassoccnt}% Version 1.2 or higher, current version is 1.7

\NewTotalDocumentCounter{appendixchapters}
\DeclareTotalAssociatedCounters{chapter}{truechapters,totalchapters}

\makeatletter
\g@addto@macro\appendix{%
  \SuspendCounters{truechapters}
  \AddAssociatedCounters{chapter}{appendixchapters}
}
\makeatother

\begin{document}

\frontmatter

There are \TotalValue{totalchapters} total chapters.

There are \TotalValue{appendixchapters} appendix chapters.

There are \TotalValue{truechapters} true chapters.

\mainmatter

\chapter{A}
\chapter{B}
\appendix
\chapter{C}
\chapter{D}
\chapter{E}
\chapter{F}
\chapter{G}
\chapter{H}
\chapter{I}

\end{document}