Why is showonlyrefs in mathtools not working this way

mathtools

I want to only show equations that I label/ref later in text. However I am doing something wrong, as there is not equation number shown, although I referenced it:

\documentclass[a4paper]{article}

\usepackage{mathtools}
\mathtoolsset{showonlyrefs}

\begin{document}
Here have an equation:
\begin{align}
A=B\label{eq:AB}\\
C=D
\end{align}
Only number equation \ref{eq:AB}.
\end{document}

which results in

Without \mathtoolsset{showonlyrefs} it looks fine but also equation C=D is displayed as (2):

What should I do to solve this issue? I want that it looks exactly like in the second picture but without the (2).

Best Answer

You need \eqref not \ref to trigger the showonlyrefs processing.

Related Solutions

[Tex/LaTex] Mathtools’ showonlyrefs fails with subequations

A workaround might be to label the two inner equations and use \noeqref to silently reference them. At the moment showonlytags does not take subequations into account, and might be difficult to implement.

Here is how showonlyrefs works. \eqref sets a special marker label to mark a given label referred to. mathtools changes the manner in which the equation numbers are typeset to see if the local label has been marked. If not it is not typeset.

The problem here is that the outer label will never be seen by the eq number typesetter within the gather.

EDIT: this works. BTW: next time please post a minimal example not a sniplet, I have no idea what \im is.

\documentclass[a4paper]{article}
\usepackage{mathtools}
\mathtoolsset{showonlyrefs=true,showmanualtags=true}
\begin{document}
\begin{subequations}\label{eq:sub}
  \noeqref{eq:1,eq:2}
  \begin{gather}
    \frac{\text{d}b_1}{\text{d}z} - \beta_1b_1 = C_{12}b_2,\label{eq:1}\\
    \frac{\text{d}b_2}{\text{d}z} - \beta_2b_2 = C_{21}b_1.\label{eq:2}
  \end{gather}
\end{subequations}
\eqref{eq:sub}
\end{document}

[Tex/LaTex] Package mathtools with showonlyrefs switch swallows parts of equation numbers in appendices

For this feature of \mathtools to work you need to reference the equations using \eqref, not \ref.

\documentclass{revtex4}

\usepackage{mathtools}
\mathtoolsset{showonlyrefs}

\begin{document}
\section{section}
See \eqref{eqn a b} and \eqref{eqn b c}.

\begin{align}
a=b \label{eqn a b}
\end{align}

\begin{appendix}
\section{appendix}

\begin{align}
b=c \label{eqn b c}
\end{align}
\end{appendix}

\end{document}

Sample output

Best Answer

Related Solutions

[Tex/LaTex] Mathtools’ showonlyrefs fails with subequations

[Tex/LaTex] Package mathtools with showonlyrefs switch swallows parts of equation numbers in appendices

Related Question