When I try to reference figures, eg "see Figure~\ref{lattice1}", the output it "Figure ??". Did I label it wrong?

Question

\documentclass{article}
 \begin{document}

\begin{figure} %

\begin{subfigure}[b]{0.30\textwidth}
\centering

\begin{tikzpicture}[
  decoration={
    markings,
    mark=between positions 0 and 1 step 25pt with { \draw [fill] (0,0) circle [radius=2pt];}
  }
]
\path[postaction={decorate}] (0,4) to (4,4);
\path[postaction={decorate}] (0,3) to (4,3);
\path[postaction={decorate}] (0,2) to (4,2);
\path[postaction={decorate}] (0,1) to (4,1);
\path[postaction={decorate}] (0,0) to (4,0);
\draw [<->] (2.3,2) -- (1.75,2) -- (1.75,2.65);
\draw [dashed] (0, 1.5) -- (4,1.5);
\draw [dashed] (0, 2.5) -- (4,2.5);
\end{tikzpicture} 
\label{lattice1}
\caption{A lattice of sources. Equation~(\ref{G01}) is the field generated by the central row.}
\end{subfigure} %
\begin{subfigure}[b]{0.30\textwidth}
\centering
\begin{tikzpicture}[
  decoration={
    markings,
    mark=between positions 0 and 1 step 25pt with { \draw [fill] (0,0) circle [radius=2pt];}
  }
]
\path[postaction={decorate}] (0,4) to (4,4);
\path[postaction={decorate}] (0,3) to (4,3);
\path[postaction={decorate}] (0,2) to (4,2);
\path[postaction={decorate}] (0,1) to (4,1);
\path[postaction={decorate}] (0,0) to (4,0);
\draw [<->] (2.3,2) -- (1.75,2) -- (1.75,2.65);
\draw [dashed] (1.25,0) -- (1.25,4);
\draw [dashed] (2.25,0) -- (2.25,4);
\end{tikzpicture}
\label{lattice2}
\caption{A lattice of sources. Equation~(\ref{F0}) is the field generated by the central column.}
\end{subfigure} %
\begin{subfigure}[b]{0.30\textwidth}
\centering
\begin{tikzpicture}[
  decoration={
    markings,
    mark=between positions 0 and 1 step 25pt with { \draw [fill] (0,0) circle [radius=2pt];}
  }
]
\path[postaction={decorate}] (0,4) to (4,4);
\path[postaction={decorate}] (0,3) to (4,3);
\path[postaction={decorate}] (0,2) to (4,2);
\path[postaction={decorate}] (0,1) to (4,1);
\path[postaction={decorate}] (0,0) to (4,0);
\draw [<->] (2.3,2) -- (1.75,2) -- (1.75,2.65);
\draw [dashed] (1.25,0) -- (1.25,4);
\draw [dashed] (2.25,0) -- (2.25,4);
\draw [dashed] (0, 1.5) -- (4,1.5);
\draw [dashed] (0, 2.5) -- (4,2.5);
\end{tikzpicture} 
\label{lattice3}
\caption{A lattice of sources. Equation~(\ref{G0}) is the field generated close to the central source.}
\end{subfigure} %
\label{lattice}

\end{figure}

\end{document}

The \label should always go after \caption; see Why does an environment's label have to appear after the caption? — egreg, May 12 '14 at 08:42

score 0 · Answer 1 · answered May 12 '14 at 08:17

0

You have to compile twice your document.

First time you'll have the creation of some files. They indicate where you have label, section, ...

So the second time the reference will appear

answered May 12 '14 at 08:17

Romain Picot

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I've compiled it several times, there's no change to the references – rachel May 12 '14 at 08:20
I've just notice you write \ref{G0} but never \label{G0}. Is write somewhere else or not? In other way you'll have to make them paired. – Romain Picot May 12 '14 at 08:25

When I try to reference figures, eg "see Figure~\ref{lattice1}", the output it "Figure ??". Did I label it wrong?

1 Answers1