# How to include caption in \begin{forest}…\end{forest} in LaTex

I have below code available in LaTeX, I want to add caption in \begin{forest} please suggest how to do the same.

\documentclass[review]{elsarticle}
\usepackage[edges]{forest}

\begin{document}
\begin{figure}
\begin{forest}
for tree={
align=center,
parent anchor=south,
child anchor=north,
font=\sffamily,
edge={thick, -{Stealth[]}},
l sep+=10pt,
edge path={
\noexpand\path [draw, \forestoption{edge}] (!u.parent anchor) -- +(0,-5pt) -| (.child anchor)\forestoption{edge label};
},
if level=0{
inner xsep=0pt,
tikz={\draw [thick] (.south east) -- (.south west);}
}{}
}
% Some test here

\end{forest}
\caption{Tree}
\end{figure}
\end{document}


This code gives error as below:

Extra }, or forgotten \endgroup. \end{forest}

• Please edit your question to post complete code for a minimal document. The above code will not compile if completed in the obvious way, so remember to check it works before posting! – cfr Jan 25 '18 at 2:09
• Forest abhors a vacuum: you can't leave blank lines. Is that semi-colon intentional? – cfr Jan 25 '18 at 2:11
• Did you read my comment? You can't leave a blank line. – cfr Jan 26 '18 at 23:20

Here's a working version of your example, updated for current Forest and sans the (presumably spurious) semi-colon.

Note, especially, the removal of the blank line. You cannot include a blank line in a forest. It doesn't matter whether you want a caption or not. The blank line will always give you an error.

\documentclass[border=10pt]{standalone}
\usepackage[edges]{forest}
\usetikzlibrary{arrows.meta}
\begin{document}
\begin{forest}
forked edges,
for tree={
align=center,
font=\sffamily,
edge={thick, -{Stealth[]}},
l sep+=10pt,
if level=0{
inner xsep=0pt,
tikz={\draw [thick] (.south east) -- (.south west);}
}{}
}
[Sensor Based \\ Methods
[4W1H \\ \cite{178}]
[Wearable sensor \\ \cite{179}]
[Depth sensor \\ \cite{190}]
[Smartphone  \\ sensor \\ \cite{191}]
[Time of Flight sensor \\ \cite{192}]
[Inertial sensor \\ \cite{156}]
]
\end{forest}
\end{document}


If you want a caption, switch to article and put the tree in a figure.

\documentclass{article}
\usepackage[edges]{forest}
\usetikzlibrary{arrows.meta}
\begin{document}
\begin{figure}
\centering
\begin{forest}
...
\end{forest}
\caption{Tree}\label{fig:tree}
\end{figure}
\end{document}


Please read one of the many excellent introductions to LaTeX so you get a sense of the basics.