*
* Example 1.5.2 from pp 28-29
*
open data strikes.dat
calendar 1951
data(format=free,org=columns) 1951:1 1980:1 strikes
*
* @expsmooth(alpha=a) does exponential smoothing on the input series. Note that
* there is a built-in instruction ESMOOTH which will do almost exactly this
* calculation.
*
source bdtrends.src
@expsmooth(alpha=.4) strikes / estrikes
graph(footer="Figure 1-21 Exponentially Smoothed Strike Data",overlay=dots,ovsame) 2
# estrikes
# strikes
*
* @freqsmooth(f=fraction of frequencies to retain) smooths by eliminating the
* high-frequency components in the input series
*
@freqsmooth(f=.4) strikes / fstrikes
graph(footer="Figure 1-22 Strike Data Smoothed by Elimination of High Frequencies",overlay=dots,ovsame) 2
# fstrikes
# strikes