[Tex/LaTex] Package pgf Error: Unknown arrow tip kind ‘latex’’ \path (

Question

I'm following the PGF 3.0.0 manual, and I have PGF 3.0.0 installed. In the manual, the example is under 20. Matrices and Alignment -> 20.6 Examples. I get errors for all the \path statements in the following code:

\documentclass[border=10pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric}
\usetikzlibrary{arrows.meta}
\begin{document}

\begin{tikzpicture}
[auto,
decision/.style={diamond, draw=blue, thick, fill=blue!20,
text width=4.5em,align=flush center,
inner sep=1pt},
block/.style ={rectangle, draw=blue, thick, fill=blue!20,
text width=5em,align=center, rounded corners,
minimum height=4em},
line/.style ={draw, thick, -latex’,shorten >=2pt},
cloud/.style ={draw=red, thick, ellipse,fill=red!20,
minimum height=2em}]
\matrix [column sep=5mm,row sep=7mm]
{
% row 1
\node [cloud] (expert) {expert}; &
\node [block] (init) {initialize model}; &
\node [cloud] (system) {system}; \\
% row 2
& \node [block] (identify) {identify candidate model}; & \\
% row 3
\node [block] (update) {update model}; &
\node [block] (evaluate) {evaluate candidate models}; & \\
% row 4
& \node [decision] (decide) {is best candidate}; & \\
% row 5
& \node [block] (stop) {stop}; & \\
};
\begin{scope}[every path/.style=line]
\path (init) -- (identify);
\path (identify) -- (evaluate);
\path (evaluate) -- (decide);
\path (update) |- (identify);
\path (decide) -| node [near start] {yes} (update);
\path (decide) -- node [midway] {no} (stop);
\path [dashed] (expert) -- (init);
\path [dashed] (system) -- (init);
\path [dashed] (system) |- (evaluate);
\end{scope}
\end{tikzpicture}

\end{document}  

Answer 1

You need

\usetikzlibrary{arrows}

and

-latex'

most probably, when doing the copy-paste from the original code, you got an incorrect character ’ in -latex’.

The complete code:

\documentclass[border=10pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric}
\usetikzlibrary{arrows.meta,arrows}
\begin{document}

\begin{tikzpicture}
[auto,
decision/.style={diamond, draw=blue, thick, fill=blue!20,
text width=4.5em,align=flush center,
inner sep=1pt},
block/.style ={rectangle, draw=blue, thick, fill=blue!20,
text width=5em,align=center, rounded corners,
minimum height=4em},
line/.style ={draw, thick, -latex',shorten >=2pt},
cloud/.style ={draw=red, thick, ellipse,fill=red!20,
minimum height=2em}]
\matrix [column sep=5mm,row sep=7mm]
{
% row 1
\node [cloud] (expert) {expert}; &
\node [block] (init) {initialize model}; &
\node [cloud] (system) {system}; \\
% row 2
& \node [block] (identify) {identify candidate model}; & \\
% row 3
\node [block] (update) {update model}; &
\node [block] (evaluate) {evaluate candidate models}; & \\
% row 4
& \node [decision] (decide) {is best candidate}; & \\
% row 5
& \node [block] (stop) {stop}; & \\
};
\begin{scope}[every path/.style=line]
\path (init) -- (identify);
\path (identify) -- (evaluate);
\path (evaluate) -- (decide);
\path (update) |- (identify);
\path (decide) -| node [near start] {yes} (update);
\path (decide) -- node [midway] {no} (stop);
\path [dashed] (expert) -- (init);
\path [dashed] (system) -- (init);
\path [dashed] (system) |- (evaluate);
\end{scope}
\end{tikzpicture}

\end{document}