dplR (version 1.4.9)

morlet: Perform a Continuous Morlet Wavelet Transform

Description

This function performs a continuous wavelet transform on a time series.

Usage

morlet(y1,x1=seq_along(y1),p2=NULL,dj=0.25,siglvl=0.95)

Arguments

y1

Numeric. Series to be transformed.

x1

Numeric. A vector of values giving the years for the plot. Must be the same length as length(y1).

p2

Numeric. The number of power of two to be computed for the wavelet transform. Calculated from legnth of y1 if NULL.

dj

Numeric. sub-octaves per octave calculated.

siglvl

level for the significance test.

Value

• A list containing:
• y
  Numeric. The original time series.
• x
  Numeric. The time values.
• wave
  Complex. The wavelet transform.
• coi
  Numeric. The cone of influence.
• period
  Numeric. The period.
• Scale
  Numeric. The scale.
• Signif
  Numeric. The significant values.
• Power
  Numeric. The squared power.

Details

This performs a continuous wavelet transform of a time series. This function is typically invoked with wavelet.plot.

References

Torrence, C. and Compo, G.P. (1998) A practical guide to wavelet analysis. Bulletin of the American Meteorological Society, 79: 61--78.

See Also

wavelet.plot

Examples

data(ca533)
ca533.rwi <- detrend(rwl = ca533, method = "ModNegExp")
ca533.crn <- chron(ca533.rwi, prefix = "CAM", prewhiten = FALSE)
Years <- as.numeric(rownames(ca533.crn))
CAMstd <- ca533.crn[, 1]
out.wave <- morlet(y1=CAMstd, x1=Years, dj=0.1, siglvl=0.99)