sunspot                package:stats                R Documentation

Yearly Sunspot Data, 1700-1988, and
Monthly Sunspot Data, 1749-1997

Description:

     Monthly and yearly number of sunspots.

Usage:

     data(sunspot)

Format:

     The univariate time series 'sunspot.year' and 'sunspot.month'
     contain 289 and 2988 observations, respectively. The objects are
     of class '"ts"'.

Source:

     Monthly data: Sunspot Index Data Center, World Data Center-C1 For
     Sunspot Index Royal Observatory of Belgium, Av. Circulaire, 3,
     B-1180 BRUSSELS <URL:
     http://www.oma.be/KSB-ORB/SIDC/sidc_txt.html>

     Yearly data: H. Tong (1996) _Non-Linear Time Series_. Clarendon
     Press, Oxford, p. 471.

References:

     Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) _The New S
     Language_. Wadsworth & Brooks/Cole.

See Also:

     'sunspot.month' is a longer version of 'sunspots' that runs until
     1988.

Examples:

     ## Compare the monthly series 
     data(sunspots)
     data(sunspot)
     plot (sunspot.month, main = "sunspot.month [stats]", col = 2)
     lines(sunspots) # "very barely" see something

     ## Now look at the difference :
     all(tsp(sunspots)     [c(1,3)] ==
         tsp(sunspot.month)[c(1,3)]) ## Start & Periodicity are the same
     n1 <- length(sunspots)
     table(eq <- sunspots == sunspot.month[1:n1]) #>  132  are different !
     i <- which(!eq) 
     rug(time(eq)[i])
     s1 <- sunspots[i] ; s2 <- sunspot.month[i]
     cbind(i = i, sunspots = s1, ss.month = s2,
           perc.diff = round(100*2*abs(s1-s2)/(s1+s2), 1))

