*
* Example 7/4/3 from pp 354-357
*
open data pollutn.dat
data(format=free,org=columns) 1 130 pollutn
*
graph(footer="Figure 7-22 Monthly Shipments of Pollution Equipment")
# pollutn
*
set logp = log(pollutn)
graph(footer="Figure 7-23 Logarithms of Data from Figure 7-22")
# logp
*
@bjident(diffs=1,number=40) logp