http://colah.github.io/posts/2014-03-NN-Manifolds-Topology/
http://cs.stanford.edu/people/karpathy/convnetjs//demo/classify2d.html
http://playground.tensorflow.org/#activation=tanh&batchSize=10&dataset=circle®Dataset=reg-plane&learningRate=0.03®ularizationRate=0&noise=0&networkShape=8,2&seed=0.49146&showTestData=false&discretize=false&percTrainData=50&x=true&y=true&xTimesY=true&xSquared=true&ySquared=true&cosX=false&sinX=true&cosY=false&sinY=true&collectStats=false&problem=classification&initZero=false&hideText=false
http://colah.github.io/posts/2015-08-Backprop/