[R] ts; decompose; plot and title

[Alberto Monteiro]

Is there any way to give a "decent" title after I plot something
generated by decompose?

For example:

# generate something with period 12
x <- rnorm(600) + sin(2 * pi * (1:600) / 12)

# transform to a monthy time series
y <- ts(x, frequency=12, start=c(1950,1))

# decompose
z <- decompose(y)

# plot
plot(z)

Now, the title is the ugly "Decomposition of additive time series".
How can do this with a decent title, like "Analysis of UFO abductions"?

Alberto Monteiro