I have created a histogram plot with pgfplots as following
\begin{tikzpicture}
\begin{axis}[small,ymin=0,title=\texttt{hist}]
\addplot [
hist,
fill=orange!75,
draw=orange!50!black]
table [y index=0] {FC.dat};
\end{axis}
\end{tikzpicture}
%
\begin{tikzpicture}
\begin{axis}[small,ymin=0, title=\texttt{hist=density}]
\addplot [
hist=density,
fill=orange!75,
draw=orange!50!black]
table [y index=0] {FC.dat};
\end{axis}
\end{tikzpicture}
FC.dat is the file where the simulation results are stored. There is no specific function to fitting. So maybe connect the central point of each bar is a good idea.

I am wondering if there is any way to add a fitting line/envelop to the bar type histogram just as the one I found
Thank you for your help!
