Chapter ref with LaTeX

Question

In LaTeX, we can say something like:

"See equation \ref{eq} on page \pageref{eq}..."

Is there any way to do:

"See equation \ref{eq} in chapter \chapterref{eq}..."

Answer 1

You can do this with the zref package. Here is an example use:

\documentclass{book}
\usepackage{zref-user}
\makeatletter
\zref@newprop{chapter}{\thechapter}
\zref@newprop{chaptertype}{\@chapapp}% as suggested by Danie Els
\zref@addprop{main}{chapter,chaptertype}
\makeatother
\begin{document}
\chapter{ch1}
  ch1
\chapter{ch2}
  ch2
  \begin{equation}\zlabel{x1}
     x=1
  \end{equation}
\chapter{ch3}
  See equation~\zref{x1} in chapter~\zref[chapter]{x1}.
  Or, Danie's suggestion (in case you move equations between
  chapters and appendices): 
  See equation~\zref{x1} in \zref[chaptertype]{x1}~\zref[chapter]{x1}
\end{document}

Answer 2

As meep.meep already posted the nameref can be used to reference to the name of the chapter. However, to get it right you need to label and reference the chapter manually and not use the label of the equation.

\documentclass{report}
\usepackage{nameref}
\usepackage[english]{babel} 
\begin{document}

\chapter{Introduction}\label{chap:intro}

\begin{equation}
  E = m\cdot c^2 \label{eq:emcsq}
\end{equation}

\chapter{Other}\label{chap:other}

% By name: "See equation 1.1 in chapter Introduction."
See equation~\ref{eq:emcsq} in chapter~\nameref{chap:intro}.


% By number: "See equation 1.1 in chapter 1."
See equation~\ref{eq:emcsq} in chapter~\ref{chap:intro}.

% Or both: "See equation 1.1 in chapter 1 ``Introduction''."
See equation~\ref{eq:emcsq} in chapter~\ref{chap:intro} ``\nameref{chap:intro}''.


\end{document}

The ~ before \ref is to prevent a line break just at this position.

Answer 3

Hyperref offers \autoref which will turn \autoref{chap:foo} into "chapter X"

\documentclass{book}
\usepackage{hyperref}
\begin{document}
\chapter{Foo}
\label{chap:foo}

This is the beginning of \autoref{chap:foo}
\end{document}

Produces:

To edit how hyperref references appear, see answers to this question

Cleverref is another package that offers this sort of functionality.

The LaTeX wikibook has details on various cross-referencing options.

Answer 4

You can solve this using the package nameref (which you don't have to load, if you use hyperref:

\documentclass{article}
\usepackage{nameref}
\usepackage[english]{babel} 
\begin{document}

\section{Testsection}

\begin{equation}
x=y 
\label{eq:test}
\end{equation}

See equation  \ref{eq:test}  in  section \nameref{eq:test}.

\end{document}

EDIT: I just noted, that if you also have a \subsection{text} then \namerefwould refer to this rather than the section. If I find the solution to this, I'll supplement it.

Answer 5

I can see two somewhat manual ways to do it:
1) Introducing an additional counter, that passes the number of the chapter containing the equation:

% in preamble
\newcounter{einst-chap}

% around the equation
E=mc^2 \label{einst} \setcounter{einst-chap}{\value{chapter}}

% and to reference
See equation \ref{einst} in chapter \arabic{einst-chap}...

However, you have to take care of the format (eg. you'd have to type \Roman{einst-chap} if you had chapter I, chapter II etc.), which makes this solution not fully automatic.

2) Storing the adequate value of \thechapter (which includes the format as well as possible superdivisions, eg. chapter A#3), using \edef:

% just after the equation
\edef\einstChap{\thechapter}

% and to reference
See equation \ref{einst} in chapter \einstChap...

Answer 6

You can use labels to sections and subsections, then refer to them like you'd refer to any other float, see below:

\section{Introduction}
\subsection{Background}
\label{sec:bg}

tesagahgshlgasghagö as seen in \ref{sec:bg} ......

Answer 7

The refstyle package has this functionality. It will correctly reference an Appendix also if your label is such. You can also link it to varioref. Please read the documentaion.

\documentclass{book}
\usepackage[nokeyprefix]{refstyle}

\begin{document}
\mainmatter
\chapter{First chapter}\label{chp:Chp1}
\Eqref{eq:Einst} in \chapref{chp:Chp1} and \eqref{eq:Feyn} in \chapref{chp:App1} it is ...
\begin{equation}
  E=mc^2 \label{eq:Einst}
\end{equation}

\appendix
\chapter{First Appendix}\label{chp:App1}
\begin{equation}
  e^{i\pi}-1 = 0 \label{eq:Feyn}
\end{equation}

\end{document}

This gives:

Answer 8

Put these commands in the preamble:

\newcommand{\chap}[1]{\hyperref[#1]{Chapter \ref{#1}}}
\newcommand{\Chap}[1]{\hyperref[#1]{Chapter \ref{#1}}, \nameref{#1}}
\newcommand{\chaps}[2]{\hyperref[#1]{Chapters \ref{#1} \& \ref{#2}}}

then the text looks something like

In \chap{C4} we proved that... and in \chaps{C2}{C1} we claimed that...

etc...