dropFreqs {multitaper} | R Documentation |
A utility function to truncate the frequencies in a spectral estimate. This utility is used before calling plot(), to increase the visual frequency resolution of a plot by truncating frequencies outside a particular band of interest. This function is not a filter, but rather a utility to allow R to 'zoom' a spectrum plot to a certain frequency band.
dropFreqs(spec, minFreq, maxFreq)
spec |
A spectrum object 'obj', of class spec, mtm, or mtm.coh. |
minFreq |
The lower bound for the frequency band to be retained, in the same units as the obj$freq array. |
maxFreq |
The upper bound for the frequency band to be retained, also in the same units as the obj$freq array. |
data(willamette) mtm1 <- spec.mtm(willamette, nw=4.0, k=8, plot=FALSE, deltat=1.0, dtUnits="month") mtm2 <- dropFreqs(mtm1, 0.1, 0.4) plot(mtm2) # another option plot(dropFreqs(mtm1, 0.1, 0.4)) # using sine tapers mtm.sine <- spec.mtm(willamette, k=10, plot=FALSE, deltat=1.0, dtUnits="month", taper="sine", sineAdaptive=FALSE, sineSmoothFact=0.05) plot(dropFreqs(mtm.sine, 0.1, 0.4))