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This is a follow-up on the answers here. I found two cases where the proposed solutions fail, and I am looking for ways to address it. Consider the MWE:

\documentclass{article}
\usepackage{etoolbox}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}

\long\def\ignoreThis#1{%
  \begingroup
  \setbox0\vbox{{\everypar{}
      \begin{minipage}{\linewidth}
        #1\end{minipage}}}%
\endgroup}%


\newcounter{mycounter}
\begin{document}
Note that \ignoreThis{this text is not shown but \addtocounter{mycounter}{5}}
side effects are processed: \themycounter
\end{document}

This works well except in two cases that I have identified (I am sure there are more as these seem related to output to aux files).

\ignoreThis{\begin{equation}
    \label{eq} A=B \end{equation}
  Reference inside \ref{eq}.}

This causes the warning Reference 'eq' on page 1 undefined. I could redefine \ref locally in \ignoreThis, but I doubt this is a good a solution. Another more critical issue is caused by pgfplots:

\ignoreThis{\begin{tikzpicture}\begin{axis}
      \addplot[only marks,mark=*]%
      table[x=x, y=y] {x  y
        2 4
        4 4
        3 3};
    \end{axis}\end{tikzpicture}}

I get the error Package pgfplots Error: Could not read table file. I am able to workaround this issue by defining the table outside \ignoreThis and using it in a plot.

Is there a better way to fix these issues?

Tohiko
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    \include is designed for this if you omit a section with includeonly all labels and counters are preserved – David Carlisle Feb 11 '22 at 13:21
  • Oh I didn't know \include preserves counters. Yes, that does seem to work. Although, \include adds a \clearpage before and after, but maybe there is a way to disable that. More importantly, would this mean that I have to create (and keep track of) a separate file every time I want to hide part of my document? In my use case, I actually control the inclusion of the content inside my command with a toggle. And I actually use this command tens of times (to hide solutions to questions in an exam paper). – Tohiko Feb 11 '22 at 13:37
  • yes include needs separate files and a clearpage so it is not for all use cases – David Carlisle Feb 11 '22 at 13:44
  • There is a way of doing it in LuaTeX. Basically, you can inspect the corresponding glyph nodes and vlist nodes generated by the content in \ignoreThis and replace them with empty nodes of the same dimensions. Unfortunately I do not have a lot of time recently and I am not good enough in LuaTeX to give you an answer quickly. Maybe you can rephrase your question in LuaTeX-related form and consult with some of the LuaTeX experts here. – Alan Xiang Feb 27 '22 at 17:14

0 Answers0