R: Monthly Sunspot Data, from 1749 to "Present"

sunspot.month {datasets} | R Documentation

## Monthly Sunspot Data, from 1749 to "Present"

### Description

Monthly numbers of sunspots, as from the World Data Center, aka SIDC. This is the version of the data that will occasionally be updated when new counts become available.

### Usage

    sunspot.month

### Format

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

### Author(s)

R

### Source

WDC-SILSO, Solar Influences Data Analysis Center (SIDC), Royal Observatory of Belgium, Av. Circulaire, 3, B-1180 BRUSSELS Currently at http://www.sidc.be/silso/datafiles

### See Also

`sunspot.month` is a longer version of `sunspots`; the latter runs until 1983 and is kept fixed (for reproducibility as example dataset).

### Examples

    require(stats); require(graphics)
    ## Compare the monthly series
    plot (sunspot.month,
          main="sunspot.month & sunspots [package'datasets']", col=2)
    lines(sunspots) # -> faint differences where they overlap

    ## 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, time = time(sunspots)[i], sunspots = s1, ss.month = s2,
          perc.diff = round(100*2*abs(s1-s2)/(s1+s2), 1))

    ## How to recreate the "old" sunspot.month (R <= 3.0.3):
    .sunspot.diff <- cbind(
        i = c(1202L, 1256L, 1258L, 1301L, 1407L, 1429L, 1452L, 1455L,
              1663L, 2151L, 2329L, 2498L, 2594L, 2694L, 2819L),
        res10 = c(1L, 1L, 1L, -1L, -1L, -1L, 1L, -1L,
              1L, 1L, 1L, 1L, 1L, 20L, 1L))
    ssm0 <- sunspot.month[1:2988]
    with(as.data.frame(.sunspot.diff), ssm0[i] <<- ssm0[i] - res10/10)
    sunspot.month.0 <- ts(ssm0, start = 1749, frequency = 12)

[Package datasets version 3.1.2 Index]