RSEIS (version 3.7-4)

MTMgabor: Evolutive MTM Spectrum

Description

Time varying Auto-Regressive Spectrum (Gabor Transform) using MTM

Usage

MTMgabor(a, dt = 0, ppoint=95 , numf = 1024, Ns = 0, Nov = 0, fl = 0, fh = 10)

Arguments

a

signal

dt

sample rate interval (s)

ppoint

percent confidence for F-test (default=95)

numf

Number of frequencies

Ns

Number of sample in sub-window

Nov

Number of sample to overlap

fl

low frequency to display

fh

high frequency to display

Value

List

sig

input signal

dt

deltat

numfreqs

Number of frequencies output

wpars

input parameters list(Nfft=numfreqs, Ns=Ns, Nov=Nov, fl=fl, fh=fh)

DSPEC

spectrum image

HIMAT

matrix with high values of F-test at 90 percent confidence

DOFMAT

Matrix image of degrees of freedom

FVMAT

Matrix image of F-test values

kdof

test degrees of freedom=2*nwin-2

ppoint

percentage point for confidence bounds

freqs

output frequencies (y axis)

tims

output times (x-axis)

Details

This is a spectrogram function similar to the Gabor Transform but uses the MTM (multi-taper method) for spectrum estimation. This is a non-interactive version of MTM.drive.

References

Percival and Walden;

Lees, J. M. and Park, J., 1995: Multiple-taper spectral analysis: A stand-alone C-subroutine, Computers \& Geology, 21(2), 199-236.

Percival, Donald B.,Walden, Andrew T. (1993):Spectral Analysis for Physical Applications,Cambridge University Press, Cambridge, 583p.

See Also

evolfft, evolMTM, MTM.drive, GETARAIC, doGABOR.AR, DOsgram, doGABOR.MTM

Examples

# NOT RUN {

# }
# NOT RUN {
data(KH)
###   swig(KH)

Xamp <- KH$JSTR[[1]]
Nfft <- 1024   ###  fft length
Ns <- 512      ###  number of samples in a window
Nov <- 480    ###  number of samples of overlap per window
fl <- 0        ###  low frequency to return
fh <- 12     ###  high frequency to return
 dt  <-  KH$dt[1]


EV <-   MTMgabor(Xamp, dt = dt, numf =Nfft , Ns = Ns, Nov = Nov, fl = fl, fh= fh)

PE   <- plotevol(EV, log=1, fl=0.01, fh=fh, col=rainbow(100),
              ygrid=FALSE, STAMP="", STYLE="ar")

# }
# NOT RUN {

# }