#Spectrum, bandwith and variance

a<-sin((1:1000)/10)

plot(a,type="l")

spectrum(a)

spectrum(a,spans=10)

spectrum(a,spans=30)

a<-sin((1:1000)/10)*4+rnorm(1000)

plot(a,type="l")

spectrum(a)

spectrum(a,spans=10,main="spans=10")

spectrum(a,spans=30,main="spans=30")

spectrum(a,spans=100,main="spans=100")