eha {astrochron}R Documentation

Evolutive Harmonic Analysis & Evolutive Power Spectral Analysis

Description

Evolutive Harmonic Analysis & Evolutive Power Spectral Analysis using the Thomson multitaper method (Thomson, 1982)

Usage

eha(dat,tbw=2,pad,fmin,fmax,step,win,demean=T,detrend=T,siglevel=0.90,
    sigID=F,ydir=1,output=0,pl=1,palette=1,centerZero=T,ncolors=100,xlab,ylab,
    genplot=2,verbose=T)

Arguments

dat

Stratigraphic series to analyze. First column should be location (e.g., depth), second column should be data value.

tbw

MTM time-bandwidth product (<=10)

pad

Pad with zeros to how many points? Must not factor into a prime number >23. Maximum number of points is 200,000.

fmin

Smallest frequency for analysis and plotting.

fmax

Largest frequency for analysis and plotting.

step

Step size for EHA window, in units of space or time.

win

Window size for EHA, in units of space or time.

demean

Remove mean from data series? (T or F)

detrend

Remove linear trend from data series? (T or F)

siglevel

Significance level for peak identification/filtering (0-1)

sigID

Identify signficant frequencies on power, amplitude, and probabilty plots. Only applies when one spectrum is calculated. (T or F)

ydir

Direction for y-axis in EHA plots (depth,height,time). -1 = values increase downwards (slower plotting), 1 = values increase upwards

output

Return output as new data frame? 0=no; 1=all results; 2=power; 3=amplitude; 4=probability; 5=significant frequencies (only for one spectrum); 6=significant frequencies and their probabilities (only for one spectrum)

pl

Plot logarithm of spectral power (1) or linear spectral power (2)?

palette

What color palette would you like to use? (1) rainbow, (2) grayscale, (3) blue, (4) red, (5) blue-white-red (if values are negative and positive, white is centered on zero)

centerZero

Center color scale on zero (use an equal number of postive and negative color divisions)? (T or F)

ncolors

Number of colors steps to use in palette.

xlab

Label for x-axis. Default = "Frequency"

ylab

Label for y-axis. Default = "Location"

genplot

Plotting options. 0= no plots; 1= power, amplitude, f-test, probability; 2=data series, power, amplitude, probability; 3= data series, power, normalized amplitude (maximum in each window normalized to unity), normalized amplitude filtered at specified siglevel; 4= data series, normalized power (maximum in each window normalized to unity), normalized amplitude (maximum in each window normalized to unity), normalized amplitude filtered at specified siglevel

verbose

Verbose output? (T or F)

References

Thomson, D. J., 1982, Spectrum estimation and harmonic analysis, Proc. IEEE, 70, 1055-1096, doi:10.1109/PROC.1982.12433.

See Also

extract, lowspec, mtmAR, mtmML96, periodogram, trackFreq and traceFreq

Examples

## as an example, evaluate the modelA
data(modelA)

## interpolate to even sampling interval of 0.075 m
ex1=linterp(modelA, dt=0.075)
  
## perform EHA with a time-bandwidth parameter of 2, using an 7.95 meter window, 0.15 m step, 
## and pad to 1000 points
## set labels for plots (optional)
eha(ex1,tbw=2,win=7.95,step=0.15,pad=1000,xlab="Frequency (cycles/m)",ylab="Height (m)")

## for comparison generate spectrum for entire record, using time-bandwidth parameter of 3, and 
## pad to 5000 points
## start by making a new plot
pl(1)
eha(ex1,tbw=3,win=38,pad=5000,xlab="Frequency (cycles/m)")

[Package astrochron version 1.0 Index]