我的文档中某处有一个定理标记theoremA为带有数字2.21。稍后，我想将另一个计数器设置为该特定数字21。
首先，我尝试了，\setcounterref{newcounter}{reference}但它没有按我预期的那样工作：theoremA具有计数器值2.21并\setcounterref设置newcounter为2而不是21。
为了修复这个问题，我尝试了，虽然的值正确，但还是\setcounter{theorem}{\StrBehind{\getrefnumber{orbitcomeagre}}{.}}会出现错误。Missing number, treated as zero\StrBehind{\getrefnumber{orbitcomeagre}}{.}21
有人对我如何修复此问题有什么建议吗？
答案1
也许我忽略了一个重要的复杂因素，但我认为您需要做的就是（a）scratchcounter在序言中定义一个名为的“临时”计数器变量，以及（b）使用如下指令
\setcounter{scratchcounter}{\value{theorem}}
紧接着所讨论的定理，将定理的编号（减去“前缀”）存储在名为 的计数器中scratchcounter。其值可通过 访问文档中的其他地方\thescratchcounter。
\documentclass{article}
\usepackage{amsthm} % or: "\usepackage{ntheorem}"
\newtheorem{theorem}{Theorem}[section]
\newcounter{scratchcounter} % define the scratch counter
\begin{document}
\setcounter{section}{2} % just for this example
\setcounter{theorem}{20}
\begin{theorem}[Pythagoras] \label{thm:pyth}
$a^2+b^2=c^2$.
\end{theorem}
\setcounter{scratchcounter}{\value{theorem}} % Store value of 'theorem' counter
\bigskip\noindent
Later on \dots\ the value of the ``scratch'' counter is \thescratchcounter.
\end{document}
答案2
这个想法\StrBehind很好，但是你必须以不同的方式使用它。
\StrBehind{\getrefnumber{orbitcomeagre}}{.}[\orbitcomeagrenumber]
\setcounter{theorem}{0\orbitcomeagrenumber}
这0是为了避免在引用尚未定义且\StrBehind不会输出任何内容时出现问题。
\documentclass{article}
\usepackage{xstring,refcount}
\newtheorem{theorem}{Theorem}[section]
\newcounter{mycount}
\begin{document}
\setcounter{section}{1}
\section{A section}
\setcounter{theorem}{20}
\begin{theorem}\label{orbitcomeagre}
A theorem.
\end{theorem}
See Theorem~\ref{orbitcomeagre}.
\StrBehind{\getrefnumber{orbitcomeagre}}{.}[\orbitcomeagrenumber]
\setcounter{mycount}{0\orbitcomeagrenumber}
See Theorem~\themycount.
\end{document}
“抽象”版本：
\documentclass{article}
\usepackage{xstring,refcount}
\newtheorem{theorem}{Theorem}[section]
\newcounter{mycount}
\newcommand{\setcountertoref}[2]{%
\begingroup
\StrBehind{\getrefnumber{#2}}{.}[\setcountertoreftemp]%
\setcounter{#1}{0\setcountertoreftemp}%
\endgroup
}
\begin{document}
\setcounter{section}{1}
\section{A section}
\setcounter{theorem}{20}
\begin{theorem}\label{orbitcomeagre}
A theorem.
\end{theorem}
See Theorem~\ref{orbitcomeagre}.
\setcountertoref{mycount}{orbitcomeagre}
See Theorem~\themycount.
\end{document}
答案3
以下解决方案的\extractthmnum{<cnt>}{<ref>}实现方式与refcount的\setcounterref：
\documentclass{article}
\newtheorem{theorem}{Theorem}[section]
\newcounter{mycount}
\makeatletter
\def\@extractthmnum#1.#2{#2}
\newcommand{\extractthmnum}[2]{% \extractthmnum{<cnt>}{<ref>}
\setcounter{#1}{0}% Default
\ifcsname r@#2\endcsname
\edef\@tempa{\csname r@#2\endcsname}% Extract complete reference
\edef\@tempa{\expandafter\@firstoftwo\@tempa}% Extract number
\setcounter{#1}{\expandafter\@extractthmnum\@tempa}% Strip number
\fi
}
\makeatother
\begin{document}
\setcounter{section}{1}
\section{A section}
\setcounter{theorem}{20}
\begin{theorem}\label{thm:theorem}
A theorem.
\end{theorem}
See Theorem~\ref{thm:theorem}.
\extractthmnum{mycount}{thm:theorem}%
See Theorem~\themycount.
\end{document}