Diagram Render API

% Neural Network Architecture
\begin{tikzpicture}[shorten >=1pt,->,draw=black!50,node distance=2.5cm]
    \tikzstyle{every pin edge}=[<-,shorten <=1pt]
    \tikzstyle{neuron}=[circle,fill=black!25,minimum size=17pt,inner sep=0pt]
    \tikzstyle{input neuron}=[neuron, fill=green!50];
    \tikzstyle{output neuron}=[neuron, fill=red!50];
    \tikzstyle{hidden neuron}=[neuron, fill=blue!50];

    % Draw Input Nodes
    \foreach \name / \y in {1,...,2}
        \node[input neuron, pin=left:Input \y] (I-\name) at (0,-\y);

    % Draw Hidden Nodes
    \foreach \name / \y in {1,...,3}
        \path[yshift=0.5cm]
            node[hidden neuron] (H-\name) at (2.5cm,-\y);

    % Draw Output Node
    \node[output neuron,pin={[pin edge={->}]right:Output},right of=H-2] (O);

    % Connect input to hidden
    \foreach \source in {1,...,2}
        \foreach \dest in {1,...,3}
            \path (I-\source) edge (H-\dest);

    % Connect hidden to output
    \foreach \source in {1,...,3}
        \path (H-\source) edge (O);
\end{tikzpicture}