https://askubuntu.com/questions/917030/how-to-install-pydot-and-graphviz
Notice how nice some of the graphs are in textbooks (for example, from AIMA 3rd ed.)?
Well you could draw them too with graphviz (dot language).
Get dot here http://www.graphviz.org/Download..php
And generate the above graph by putting this in a file, e.g. simple_neural_network_diagram.dot
digraph G {
rankdir=LR
splines=line
node [fixedsize=true, label=""];
subgraph cluster_0 {
color=white;
node [style=solid,color=blue4, shape=circle];
x1 x2 x3;
label = "layer 1 (Input layer)";
}
subgraph cluster_1 {
color=white;
node [style=solid,color=red2, shape=circle];
a12 a22 a32;
label = "layer 2 (hidden layer)";
}
subgraph cluster_2 {
color=white;
node [style=solid,color=seagreen2, shape=circle];
O;
label="layer 3 (output layer)";
}
x1 -> a12;
x1 -> a22;
x1 -> a32;
x2 -> a12;
x2 -> a22;
x2 -> a32;
x3 -> a12;
x3 -> a22;
x3 -> a32;
a12 -> O
a22 -> O
a32 -> O
}
And generate it
dot -Tpng simple_neural_network_diagram.dot -o network.png