路径不会显示在 tikz

Question

我想知道为什么 (pittet)|-(model) 的路径根本不会显示出来... 有什么想法吗？ 相应的行被注释掉了 %这一行到 %这一行

\documentclass{article}

\usepackage[latin1]{inputenc}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows}
\begin{document}
\pagestyle{empty}


% Define block styles
\tikzstyle{decision} = [diamond, draw, 
    text width=4.5em, text badly centered, node distance=3cm, inner sep=0pt]
\tikzstyle{block} = [rectangle, draw, 
    text width=5em, text centered, rounded corners, minimum height=4em]
\tikzstyle{line} = [draw, -latex']
\tikzstyle{cloud} = [draw, circle, node distance=3cm,
    minimum height=2em]

\begin{figure}[!ht]
\centering\makebox[\textwidth]{
\begin{tikzpicture}[node distance = 2.5cm, auto]
    % Place nodes
    \node [block] (init) {Controlled particle deposition experiment in chamber};
    \node [cloud, left of=init, node distance=4cm] (expert) {Scenario design};
    \node [cloud, right of=init, node distance=4cm] (system) {Literature input};
    \node [block, below of=init] (identify) {CFD models};
    \node [block, below of=identify] (evaluate) {Validate against expeirment};
    \node [block, left of=evaluate, node distance=3cm] (update) {update model};
    \node [decision, below of=evaluate] (decide) {is spatial prediction within $\sigma^2$ of experiment?};
    \node [block, below of =decide,node distance=4cm] (model) {Parametric  model}; %This one
    \node [cloud,  left of=decide, node distance=6cm] (litinput) {Literature parametric input};
    \node [cloud,  right of=decide, node distance=6cm] (obsinput) {Obersvational study YAB};
\node [decision, below of=model] (map_n_to_t) {Sensitivity analysis};
  \node [block, right of=map_n_to_t, node distance=3cm] (pittet) {update model}; % to this one
   \node [block, below of=map_n_to_t, node distance=3cm] (compare) {Evaluate Model};
\node [block, below of=compare, left of =compare, node distance=3cm] (single) {Single room};
\node [block, below of=compare, right of =compare, node distance=3cm] (4bed) {Multibed room};
   \node [block, below of=compare,node distance=3cm] (stop) {Output comparison};
    % Draw edges
    \path [line] (init) -- (identify);
    \path [line] (identify) -- (evaluate);
    \path [line] (evaluate) -- (decide);
    \path [line] (decide) -| node [near start] {no} (update);
    \path [line] (update) |- (identify);
    \path [line] (decide) -- node {yes}(model);
    \path [line,dashed] (expert) -- (init);
    \path [line,dashed] (system) -- (init);
     \path [line] (decide) -- (model);
  \par[line,dashed] (pittet) -| (model);  %why won't this line show up?
 \path [line,dashed] (litinput) |- (model);
    \path [line,dashed] (obsinput) |- (model);

    \path [line]   (map_n_to_t) -- (pittet);
    \path [line]  (model)--(map_n_to_t) ;
    \path [line,dashed] (system) |- (evaluate);
\path [line]  (map_n_to_t)--(compare) ;
\path [line]  (compare) --(single);
\path [line]  (compare) --(4bed);
\path [line]  (single) --(stop);
\path [line]  (4bed) --(stop);
\end{tikzpicture}}
\smallskip
\label{fig:flowchart_chapter1}
\caption{Flowchart of model development}
\end{figure}


\end{document}