```
# NOT RUN {
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)
# }
```

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