http://www.ai-junkie.com/ann/evolved/nnt8.html
https://www.r-bloggers.com/fitting-a-neural-network-in-r-neuralnet-package/
x <- 1:10
y <- c(2,4,6,8,7,12,14,16,18,20)
lo <- loess(y~x)
plot(x,y)
lines(predict(lo), col='red', lwd=2)
http://bigdata-doctor.com/recommender-systems-101-practical-example-in-r/
http://machinelearningmastery.com/feature-selection-with-the-caret-r-package/
http://www.teglor.com/b/deep-learning-libraries-language-cm569/