sunspot.month {datasets} | R Documentation

## Monthly Sunspot Data, 1749–1997

### Description

Monthly numbers of sunspots.

### 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"`.

### Note

Prior to R 2.0.0 `sunspot.month` and `sunspot.year` were copied to the user's workspace (or elsewhere) by `data(sunspot)`. However, as package lattice has a dataset `sunspot` which can be retrieved by the same command, that usage has been removed.

### Source

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

### See Also

`sunspot.month` is a longer version of `sunspots` that runs until 1988 rather than 1983.

### Examples

    require(stats)
    ## Compare the monthly series
    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))

[Package datasets version 2.3.1 Index]