%%%------------------------------------------------------------------------------------------------------------
\begin{tikzpicture}
\begin{scope}[]
\def\neuronsep{1.3}
\tikzstyle{neuronnode} = [minimum size=1.7em,circle,draw,ublue,very thick,inner sep=1pt, fill=white,align=center,drop shadow={shadow xshift=0.1em,shadow yshift=-0.1em}]

%%% layer 1
\foreach \n in {1,...,5}{
    \node [neuronnode] (neuron0\n) at (\n * \neuronsep,0) {\tiny{$f_1$}\\[-1ex] \tiny{$\sum$}};
    \draw [-,ublue] (neuron0\n.east) -- (neuron0\n.west);
}
\foreach \n in {1,...,5}{
    \foreach \m in {1,...,5}{
        \draw [<-] (neuron0\m.south) -- ([yshift=-1.8em]neuron0\n.south);
    }
    \node [anchor=north] (x\n) at ([yshift=-1.8em]neuron0\n.south) {$x_\n$};
 {
    \draw [<-,thick] ([yshift=1.1em]neuron0\n.north) -- (neuron0\n.north);
    \node [anchor=south] (y\n) at ([yshift=1.2em]neuron0\n.north) {$y_\n$};
    }
}
\node [anchor=west] (w1label) at ([xshift=-0.5em,yshift=0.5em]x5.north east) {$\textbf{w}_1$};
\begin{pgfonlayer}{background}
\node [rectangle,inner sep=0.2em,fill=red!20] [fit = (neuron01) (neuron05)] (layer01) {};
\end{pgfonlayer}
{
\node [anchor=west] (layer01label) at ([xshift=2em]layer01.east) {\footnotesize{单层神经网络}};
}
\node[anchor=north] (arrow1) at ([yshift=0em]x3.south) {};
\draw[fill=blue!20,draw=blue!30]([xshift=-0.20em]arrow1.north west)--([xshift=0.20em]arrow1.north east)--([yshift=0.15em,xshift=0.20em]arrow1.south east)--([yshift=0.15em,xshift=0.8em]arrow1.south east) --([yshift=-0.8em]arrow1.south)--([yshift=0.15em,xshift=-0.8em]arrow1.south west)--([yshift=0.15em,xshift=-0.20em]arrow1.south west)--([xshift=-0.20em]arrow1.north west);

\end{scope}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{scope}[xshift=0.0em,yshift=-12.7em]

\def\neuronsep{1.3}

\tikzstyle{neuronnode} = [minimum size=1.7em,circle,draw,ublue,very thick,inner sep=1pt, fill=white,align=center,drop shadow={shadow xshift=0.1em,shadow yshift=-0.1em}]

%%% layer 1
\foreach \n in {1,...,5}{
    \node [neuronnode] (neuron0\n) at (\n * \neuronsep,0) {\tiny{$f_1$}\\[-1ex] \tiny{$\sum$}};
    \draw [-,ublue] (neuron0\n.east) -- (neuron0\n.west);
}

\foreach \n in {1,...,5}{
    \foreach \m in {1,...,5}{
        \draw [<-] (neuron0\m.south) -- ([yshift=-1.8em]neuron0\n.south);
    }
    \node [anchor=north] (x\n) at ([yshift=-1.8em]neuron0\n.south) {$x_\n$};
}

\node [anchor=west] (w1label) at ([xshift=-0.5em,yshift=0.5em]x5.north east) {$\textbf{w}_1$};

\begin{pgfonlayer}{background}
\node [rectangle,inner sep=0.2em,fill=red!20] [fit = (neuron01) (neuron05)] (layer01) {};
\end{pgfonlayer}

%%% layer 2

\foreach \n in {2,...,4}{
    \node [neuronnode] (neuron1\n) at (\n * \neuronsep,3.5em) {\tiny{$f_2$}\\[-1ex] \tiny{$\sum$}};
    \draw [-,ublue] (neuron1\n.east) -- (neuron1\n.west);
}

\foreach \n in {2,...,4}{
    \foreach \m in {1,...,5}{
        \draw [<-] (neuron1\n.south) -- (neuron0\m.north);
    }
    \draw [<-,thick] ([yshift=1.1em]neuron1\n.north) -- (neuron1\n.north);
    \node [anchor=south] (y\n) at ([yshift=1.25em]neuron1\n.north) {$y_\n$};
}

\node [anchor=west] (w2label) at ([xshift=-2.5em,yshift=4.6em]x5.north east) {$\textbf{w}_2$};
\node [anchor=west] (layer02label) at ([xshift=2.7em]w2label.east) {\footnotesize{两层神经网络}};
\begin{pgfonlayer}{background}
{
\node [rectangle,inner sep=0.2em,fill=ugreen!20] [fit = (neuron12) (neuron14)] (layer02) {};
}
\end{pgfonlayer}

\node[anchor=north] (arrow1) at ([yshift=0em]x3.south) {};
\draw[fill=blue!20,draw=blue!30]([xshift=-0.20em]arrow1.north west)--([xshift=0.20em]arrow1.north east)--([yshift=0.15em,xshift=0.20em]arrow1.south east)--([yshift=0.15em,xshift=0.8em]arrow1.south east) --([yshift=-0.8em]arrow1.south)--([yshift=0.15em,xshift=-0.8em]arrow1.south west)--([yshift=0.15em,xshift=-0.20em]arrow1.south west)--([xshift=-0.20em]arrow1.north west);

\end{scope}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{scope}[xshift=0.0em,yshift=-29em]

\def\neuronsep{1.3}

\tikzstyle{neuronnode} = [minimum size=1.7em,circle,draw,ublue,very thick,inner sep=1pt, fill=white,align=center,drop shadow={shadow xshift=0.1em,shadow yshift=-0.1em}]

%%% layer 1
\foreach \n in {1,...,5}{
    \node [neuronnode] (neuron0\n) at (\n * \neuronsep,0) {\tiny{$f_1$}\\[-1ex] \tiny{$\sum$}};
    \draw [-,ublue] (neuron0\n.east) -- (neuron0\n.west);
}

\foreach \n in {1,...,5}{
    \foreach \m in {1,...,5}{
        \draw [<-] (neuron0\m.south) -- ([yshift=-1.8em]neuron0\n.south);
    }
    \node [anchor=north] (x\n) at ([yshift=-1.8em]neuron0\n.south) {$x_\n$};
}

\node [anchor=west] (w1label) at ([xshift=-0.5em,yshift=0.5em]x5.north east) {$\textbf{w}_1$};

\begin{pgfonlayer}{background}
\node [rectangle,inner sep=0.2em,fill=red!20] [fit = (neuron01) (neuron05)] (layer01) {};
\end{pgfonlayer}

%%% layer 2
{
\foreach \n in {2,...,4}{
    \node [neuronnode] (neuron1\n) at (\n * \neuronsep,3.5em) {\tiny{$f_2$}\\[-1ex] \tiny{$\sum$}};
    \draw [-,ublue] (neuron1\n.east) -- (neuron1\n.west);
}

\foreach \n in {2,...,4}{
    \foreach \m in {1,...,5}{
        \draw [<-] (neuron1\n.south) -- (neuron0\m.north);
    }
}

\node [anchor=west] (w2label) at ([xshift=-2.5em,yshift=4.6em]x5.north east) {$\textbf{w}_2$};

\begin{pgfonlayer}{background}
{
\node [rectangle,inner sep=0.2em,fill=ugreen!20] [fit = (neuron12) (neuron14)] (layer02) {};
}
\end{pgfonlayer}

\node [anchor=west] (layer02label) at ([xshift=5.2em]layer02.east) {\footnotesize{三层神经网络}};
}

%%% layer 3
{
\foreach \n in {1,...,5}{
    \node [neuronnode] (neuron2\n) at (\n * \neuronsep,7em) {\tiny{$f_3$}\\[-1ex] \tiny{$\sum$}};
    \draw [-,ublue] (neuron2\n.east) -- (neuron2\n.west);
}

\foreach \n in {1,...,5}{
    \foreach \m in {2,...,4}{
        \draw [<-] (neuron2\n.south) -- (neuron1\m.north);
    }

    \node [anchor=south] (y\n) at ([yshift=1.25em]neuron2\n.north) {$y_\n$};
    \draw [<-,thick] ([yshift=1.1em]neuron2\n.north) -- (neuron2\n.north);
}

\node [anchor=west] (w3label) at ([xshift=-2.5em,yshift=7.5em]x5.north east) {$\textbf{w}_3$};

\begin{pgfonlayer}{background}
{
\node [rectangle,inner sep=0.2em,fill=blue!20] [fit = (neuron21) (neuron25)] (layer03) {};
}
\end{pgfonlayer}
}

\end{scope}
\end{tikzpicture}
%%%------------------------------------------------------------------------------------------------------------




