| % File src/library/datasets/man/sunspot.year.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2007 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{sunspot.year} |
| \docType{data} |
| \alias{sunspot.year} |
| \title{Yearly Sunspot Data, 1700--1988} |
| \description{ |
| Yearly numbers of sunspots from 1700 to 1988 (rounded to one digit). |
| |
| Note that monthly numbers are available as |
| \code{\link{sunspot.month}}, though starting slightly later. |
| } |
| \usage{ |
| sunspot.year |
| } |
| \format{ |
| The univariate time series \code{sunspot.year} contains 289 |
| observations, and is of class \code{"ts"}. |
| } |
| \source{ |
| H. Tong (1996) |
| \emph{Non-Linear Time Series}. Clarendon Press, Oxford, p.\sspace{}471. |
| } |
| \seealso{ |
| For \emph{monthly} sunspot numbers, see \code{\link{sunspot.month}} |
| and \code{\link{sunspots}}. |
| |
| Regularly updated yearly sunspot numbers are available from |
| WDC-SILSO, Royal Observatory of Belgium, at |
| \url{http://www.sidc.be/silso/datafiles} |
| } |
| \examples{ |
| utils::str(sm <- sunspots)# the monthly version we keep unchanged |
| utils::str(sy <- sunspot.year) |
| ## The common time interval |
| (t1 <- c(max(start(sm), start(sy)), 1)) # Jan 1749 |
| (t2 <- c(min( end(sm)[1],end(sy)[1]), 12)) # Dec 1983 |
| s.m <- window(sm, start=t1, end=t2) |
| s.y <- window(sy, start=t1, end=t2[1]) # {irrelevant warning} |
| stopifnot(length(s.y) * 12 == length(s.m), |
| ## The yearly series *is* close to the averages of the monthly one: |
| all.equal(s.y, aggregate(s.m, FUN = mean), tol = 0.0020)) |
| ## NOTE: Strangely, correctly weighting the number of days per month |
| ## (using 28.25 for February) is *not* closer than the simple mean: |
| ndays <- c(31, 28.25, rep(c(31,30, 31,30, 31), 2)) |
| all.equal(s.y, aggregate(s.m, FUN = mean)) # 0.0013 |
| all.equal(s.y, aggregate(s.m, FUN = weighted.mean, w = ndays)) # 0.0017 |
| } |
| \keyword{datasets} |