Smoothing is a statistical technique that helps you to spot trends in noisy data, and especially to compare trends between two or more fluctuating time series. It's a useful visualization tool that I'm pleased to see cropping up more and more in statistical graphics on the Web -- it's now a staple in econometric charts and is heavily used...


Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).