In yesterday's post, I discussed a "quick and dirty" method to smooth periodic data. However, after I smoothed the data I remarked that the smoother itself was not exactly periodic. At the end points of the periodic interval, the smoother did not have equal slopes and the method does not
Over at the SAS and R blog, Ken Kleinman discussed using polar coordinates to plot time series data for multiple years. The time series plot was reproduced in SAS by my colleague Robert Allison. The idea of plotting periodic data on a circle is not new. In fact it goes
Celebrating anniversaries is part of our culture. We celebrate the important ones – like 50 years of marriage – and the difficult ones, like going a week without chocolate. Parents celebrate the number of times a toddler uses the potty, and teenagers celebrate the weeks they have been dating. Big
