pgram {ptest} | R Documentation |
The periodogram is computed.
pgram(z)
z |
series |
Uses FFT. So if the length of z is a highly composite number, the computation is very efficient. The periodogram is computed for the Fourier frequencies, (1:nF)/n, where nF=floor(n/2), n=length(z).
Periodogram evaluated at the Fourier frequencies
A.I. McLeod
z<-sunspot.year n<-length(z) I<-pgram(z) nF<-floor(n/2) f<-(1:nF)/n plot(f, I, xlab="f", ylab="f", type="l") title(main="Periodogram for Annual Sunpots, 1700-1988")