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 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))