%
% google.tex
%
% (c) 2021 Prof Dr Andreas Müller, OST Ostschweizer Fachhochschule
%
\begin{frame}[t]
\setlength{\abovedisplayskip}{5pt}
\setlength{\belowdisplayskip}{5pt}
\frametitle{Google-Matrix}
\vspace{-20pt}
\begin{columns}[t,onlytextwidth]
\begin{column}{0.48\textwidth}
\begin{center}
\begin{tikzpicture}[>=latex,thick]

\def\r{2.4}
\coordinate (A) at (0,0);
\coordinate (B) at (0:\r);
\coordinate (C) at (60:\r);
\coordinate (D) at (120:\r);
\coordinate (E) at (180:\r);

\foreach \a in {2,...,5}{
	\fill[color=white] ({60*(\a-2)}:\r) circle[radius=0.2];
	\draw ({60*(\a-2)}:\r) circle[radius=0.2];
	\node at ({60*(\a-2)}:\r) {$\a$};
}
\fill[color=white] (A) circle[radius=0.2];
\draw (A) circle[radius=0.2];
\node at (A) {$1$};

{\color<6>{red}
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (A) -- (B);
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (A) -- (C);
}

{\color<7>{red}
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (B) -- (C);
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (B) to[out=-150,in=-30] (E);
}

{\color<8>{red}
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (C) to[out=-90,in=30] (A);
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (C) to[out=-30,in=90] (B);
}

{\color<9>{red}
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (D) -- (C);
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (D) -- (A);
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (D) -- (E);
}

{\color<10>{red}
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (E) -- (A);
	\draw[->,shorten >= 0.2cm,shorten <= 0.2cm] (E) to[out=90,in=-150] (D);
}

\end{tikzpicture}
\end{center}
\vspace{-10pt}
\renewcommand{\arraystretch}{1.1}
\uncover<5->{
\begin{align*}
H&=\begin{pmatrix}
\uncover<6->{0          }
	&\uncover<7->{0          }
	&\uncover<8->{{\color<8>{red}\frac{1}{2}}}
	&\uncover<9->{{\color<9>{red}\frac{1}{3}}}
	&\uncover<10->{{\color<10>{red}\frac{1}{2}}}\\
\uncover<6->{{\color<6>{red}\frac{1}{2}}}
	&\uncover<7->{0          }
	&\uncover<8->{{\color<8>{red}\frac{1}{2}}}
	&\uncover<9->{0          }
	&\uncover<10->{0          }\\
\uncover<6->{{\color<6>{red}\frac{1}{2}}}
	&\uncover<7->{{\color<7>{red}\frac{1}{2}}}
	&\uncover<8->{0          }
	&\uncover<9->{{\color<9>{red}\frac{1}{3}}}
	&\uncover<10->{0          }\\
\uncover<6->{0          }
	&\uncover<7->{0          }
	&\uncover<8->{0          }
	&\uncover<9->{0          }
	&\uncover<10->{{\color<10>{red}\frac{1}{2}}}\\
\uncover<6->{0          }
	&\uncover<7->{{\color<7>{red}\frac{1}{2}}}
	&\uncover<8->{0          }
	&\uncover<9->{{\color<9>{red}\frac{1}{3}}}
	&\uncover<10->{0          }
\end{pmatrix}
\\
\uncover<11->{
h_{ij}
&=
\frac{1}{\text{Anzahl Links ausgehend von $j$}}
}
\end{align*}}
\end{column}
\begin{column}{0.48\textwidth}
\begin{block}{Aufgabe}
Bestimme die Wahrscheinlichkeit $p(i)$, mit der sich ein Surfer
auf der Website $i$ befindet
\end{block}
\uncover<2->{
\begin{block}{Navigation}
$p(i) = P(i,\text{vor Navigation})$,
\uncover<3->{$p'(i)=P(i,\text{nach Navigation})$}
\uncover<4->{
\[
p'(i) = \sum_{j=1}^n h_{ij} p(j)
\]}
\end{block}}
\vspace{-15pt}
\begin{block}{Freier Wille}
\vspace{-12pt}
\[
G = \alpha H + (1-\alpha)\frac{UU^t}{n}
\]
Google-Matrix
\end{block}
\end{column}
\end{columns}
\end{frame}