cross-referencinglyx
I'm working with LyX. Do you know how to apply cross reference when using "Tex code" option in LyX?
That's the example of what I'm writing in Tex code:
\begin{table}[htbp]
\begin{threeparttable}
\caption{Title}\label{...}
\estwide{myfile.tex}{2}{c}
\end{threeparttable}
\end{table}
Where I should put the label in this case so that cross reference option can work?
I hope the question is clear…thank you for your help!
The problem is that a \label attaches itself to the last numbered element in the document -- in your case a section -- it does not correspond to the exact position in the code/PDF.
As an alternative to Werner's suggestion, is to use \hyperlink and \hypertarget from hyperref. There is as far as I know no way of accessing these via the LyX GUI however, so you have to add them in ERTs. And as hyperref is required, you have to enable that under Document --> Settings --> PDF Properties, if you haven't already.
The syntax for these commands is
\hyperlink{<name>}{<text>}
\hypertarget{<name>}{<text>}
where <name> is the label, and <text> is printed in the PDF. As there is no support for these in the GUI, you can't use LyX' cross-referencing mechanism.
An example is seen in the screenshot below. I added \hypertarget{thing}{Cool stuff!} one place, and \hyperlink{thing}{Check this out.} where I wanted the link to be. Note that <text> in the \hypertarget can be empty if you want that.
When you mention "hyperlink to the figure", I assume you're referring to the hyperlink from the LoF. Yes, that's all based on the \caption, which is set correctly. However, as is clear from your example code, inserting a newline in LyX actually creates a separate group around the caption:
\begin{figure}[h]
\noindent \begin{centering}
\includegraphics[<opts>]{<filename>}\caption{<caption>}
\par\end{centering}
\noindent \centering{}\label{<label>}
\end{figure}
From the above we can see that \caption is placed inside a centering group. Now, according to Understanding how references and labels work you'll see that \label uses \@currentlabel - a macro that is updated when you step a counter. In this case the counter is stepped as part of the call to \caption. However, this update is reverted when the group is closed, because the update is only local to the group that its used in.
So it seems you should NOT put an empty line between the \caption and \label in LyX. It's just the way LyX interprets new lines within structures that seems strange. Of course, as a GUI-like editor for LaTeX, it attempts to remove some of the code-like insertions from the user. However, with this intuitiveness comes some assumptions... something that is clearly incorrectly interpreted in this case.
Best Answer
You are not using LyX's interface for managing labels and cross-references. As such, if you're using
\label{abc}in an ERT (or "TeX code"), then you need to also use an ERT for the reference\ref{abc}as well.