[R] Growth of CRAN?

[Gabor Grothendieck]

On Sun, Apr 13, 2014 at 1:26 PM, John Fox <jfox at mcmaster.ca> wrote:
> I've attached the most recent data I have, which are from mid-2012. My
> package counts came from
> https://svn.r-project.org/R/branches/R-*-branch/tests/internet.Rout.save
> (where the * is the R version).
>


It seems that the growth is exponential but at a lower slope (of the
log curve) after 2008 than before. A linear fit to the log curve is
shown  in blue before 2008 and in red after 2008.  What happened to
result in two such distinct regimes?

Lines <- "version date        packages
1.3     2001-06-21   110
1.4     2001-12-17   129
1.5     2002-05-29   162
#1.6     2002-10-01   163
1.7     2003-05-27   219
1.8     2003-11-16   273
1.9     2004-06-05   357
2.0     2004-10-12   406
2.1     2005-06-18   548
2.2     2005-12-16   647
2.3     2006-05-31   739
2.4     2006-12-12   911
2.5     2007-04-12  1000
2.6     2007-11-16  1300
2.7     2008-03-18  1427
2.8     2008-10-18  1614  # updated
2.9     2009-04-17  1952
2.10    2009-10-26  2088
2.11    2010-04-22  2445
2.12    2010-10-15  2837
2.13    2011-04-13  3286
2.14    2011-06-20  3618
2.15    2012-07-07  4000
"
library(zoo)
zz <- read.zoo(text = Lines, header = TRUE, index = 2)[, 2]
plot(log(zz))
d <- as.Date("2008-01-01")
abline(v = d)
pre <- time(zz) < d
fo <- log(zz) ~ time(zz)
abline(lm(fo, subset = pre), col = "blue")
abline(lm(fo, subset = !pre), col = "red")