[Tex/LaTex] How to reference figure*’s subfigure?

cross-referencingfloatssubfloats

I'm writing a paper to submit a conference.

However, I am having some problems fixing non-resolved references in latex.

\begin{figure*}[ht!]

\begin{subfigure}[b]{0.3\linewidth}

    \includegraphics[width=1\linewidth]{fig/toy}

    \vspace*{-1cm} % for cosmetic change

    \label{fig:toynetwork_example}

    \caption{A toy network}

\end{subfigure}%

\begin{subfigure}[b]{0.3\linewidth}

    \includegraphics[width=1\linewidth]{fig/exampleProcedure13}

    \vspace*{-1cm} % for cosmetic change

    \label{fig:firstIterationFin}

    \caption{After first iteration}

\end{subfigure}

\begin{subfigure}[b]{0.3\linewidth}

    \includegraphics[width=1\linewidth]{fig/proposed_adjacency_matrix}

    \vspace*{-0.4cm} % for cosmetic change

    \label{fig:proposed_adjacency_matrix}

    \caption{Adjacency matrix}

\end{subfigure}%

\begin{subfigure}[b]{0.3\linewidth}

    \includegraphics[width=1\linewidth]{fig/proposed_influence_matrix}

    \vspace*{-0.4cm} % for cosmetic change

    \label{fig:proposed_influence_matrix}

    \caption{Influence matrix}

\end{subfigure}%

    \hspace*{0.2cm}

\vspace*{0.3cm} % for cosmetic change

\begin{subfigure}[b]{0.3\linewidth}

    \includegraphics[width=1\linewidth]{fig/proposed_update_order}

    \vspace*{-0.4cm} % for cosmetic change

    \label{fig:proposed_update_order}

    \caption{Update order}

\end{subfigure}%

\caption{Example network}

\label{fig:example_network_procedure}

\end{figure*}

The PDF file shows ?? rather than the reference.

Can you help me?

enter image description here

Best Answer

The \label must go after or inside the \caption command. It cannot be placed before. This is because \caption increments the relevant counter, which is what \label hooks onto. If you put the \label first, there is nothing onto which it might hook.

For example, turning your code into a (semi-)Minimal Working Example by adding a preamble and substituting standard images:

labelled subfigures

Code:

\documentclass{article}
\usepackage{graphicx,subcaption}

\begin{document}

\ref{fig:example_network_procedure}
\ref{fig:firstIterationFin}
\ref{fig:proposed_adjacency_matrix}
\ref{fig:proposed_influence_matrix}
\ref{fig:proposed_update_order}
\ref{fig:toynetwork_example}

\begin{figure*}[ht!]
  \begin{subfigure}[t]{0.3\linewidth}
    \includegraphics[width=1\linewidth]{example-image-a}

    \caption{A toy network\label{fig:toynetwork_example}}
  \end{subfigure}
  \begin{subfigure}[t]{0.3\linewidth}
    \includegraphics[width=1\linewidth]{example-image-a}

    \caption{After first iteration}\label{fig:firstIterationFin}
  \end{subfigure}
  \begin{subfigure}[t]{0.3\linewidth}
    \includegraphics[width=1\linewidth]{example-image-a}

    \caption{Adjacency matrix}\label{fig:proposed_adjacency_matrix}
  \end{subfigure}

  \begin{subfigure}[t]{0.3\linewidth}
    \includegraphics[width=1\linewidth]{example-image-a}

    \caption{Influence matrix\label{fig:proposed_influence_matrix}}
  \end{subfigure}
  \begin{subfigure}[t]{0.3\linewidth}
    \includegraphics[width=1\linewidth]{example-image-a}

    \caption{Update order}\label{fig:proposed_update_order}
  \end{subfigure}

  \caption{Example network}
  \label{fig:example_network_procedure}
\end{figure*}

\end{document}

Code

Note that I have removed every reference to an external graphic because

I don’t have them.
I don’t need them.

I also removed \usepackage{caption}, it does get already loaded by subcaption.
The chngcntr package does not interfere with this MWE.

\documentclass[11pt]{article}
\usepackage{graphicx}
\usepackage{subcaption}
\usepackage{chngcntr}
\begin{document}
\begin{figure}
  \caption{fig:before}\label{fig:before}
\end{figure}
Figure~\ref{fig:before}.

I'm trying to reference Figure~\ref{fig:regress}, subfigure~\ref{fig:linfit} and \ref{fig:quadfit} as well as \ref{fig:cubicfit} here.

\hrulefill
\begin{figure}[htp]
  \centering
  \begin{subfigure}{0.8\textwidth}
    \caption{Scatter plot fitted with straight line}
    \label{fig:linfit}
  \end{subfigure}%

  \begin{subfigure}{0.8\textwidth}
    \caption{Scatter plot fitted with 2nd degree polynomial}
    \label{fig:quadfit}
  \end{subfigure}
  \phantomcaption%                                                                                                                  either a phantom caption
%  \caption{Scatteru plots of wavelength vs. pixel position for the spectrum from night 1, fitted with polynomials of orders 1-3.}% or a real one
\end{figure}

\hrulefill
\begin{figure}[htp]
  \ContinuedFloat
  \centering
  \begin{subfigure}{0.8\textwidth}
    \caption{Scatter plot fitted with 3rd degree polynomial} 
    \label{fig:cubicfit}
  \end{subfigure}
  \caption{Scatteru plots of wavelength vs. pixel position for the spectrum from night 1, fitted with polynomials of orders 1-3.}   \label{fig:regress}
\end{figure}
\end{document}

Output

enter image description here

[Tex/LaTex] How to reference to subfigure in latex

You can use subcaption and cleveref packages...

\documentclass{scrbook}
\usepackage[demo]{graphicx}
\usepackage{subcaption}

\usepackage{cleveref}

\captionsetup[subfigure]{subrefformat=simple,labelformat=simple}
\renewcommand\thesubfigure{(\alph{subfigure})}

\setcounter{chapter}{1}

\begin{document}

  \begin{figure}[htbp!]
    \centering
      \begin{subfigure}{0.45\textwidth}
        \includegraphics[width=\textwidth]{image1}
          \caption{Nice image1}
          \label{fig:NiceImage1}
      \end{subfigure}
      \hfill
      \begin{subfigure}{0.45\textwidth}
        \includegraphics[width=\textwidth]{image1}
          \caption{Nice image 2}
          \label{fig:NiceImage2}
      \end{subfigure}
\caption{
\label{fig:NiceImage}%
Two images}
\end{figure}

Figure \ref{fig:NiceImage}

Figure \ref{fig:NiceImage} \subref{fig:NiceImage1}

\Cref{fig:NiceImage}

\Cref{fig:NiceImage1}

\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Wrong figure reference number

Code

Output

[Tex/LaTex] How to reference to subfigure in latex

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