R: Truncate mtm or mtm.coh Objects in Frequency

dropFreqs {multitaper} | R Documentation

## Truncate mtm or mtm.coh Objects in Frequency

### Description

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.

### Usage

    dropFreqs(spec, minFreq, maxFreq)

### Arguments

`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.

### Examples

    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))

[Package multitaper version 1.0-13 Index]