wt: Compute wavelet transform
In biwavelet: Conduct univariate and bivariate wavelet analyses

Description Usage Arguments Value Author(s) References Examples

Continuous wavelet transform

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wt (d, pad = TRUE, dt = NULL, dj = 1/12, s0 = 2 * dt, J1 = NULL, 
    max.scale = NULL, mother = c("morlet", "paul", "dog"), 
    param = -1, lag1 = NULL, sig.level = 0.95, sig.test = 0, do.sig=TRUE)

`d`	time series in matrix format (`n` rows x 2 columns). The first column should contain the time steps and the second column should contain the values.
`pad`	pad the values will with zeros to increase the speed of the transform. Default is TRUE.
`dt`	length of a time step.
`dj`	spacing between successive scales. Default is 1/12.
`s0`	smallest scale of the wavelet. Default is `2*dt`
`J1`	number of scales - 1.
`max.scale`	maximum scale. Computed automatically if left unspecified.
`mother`	type of mother wavelet function to use. Can be set to `morlet`, `dog`, or `paul`. Default is `morlet`.
`param`	nondimensional parameter specific to the wavelet function.
`lag1`	AR(1) coefficient of time series used to test for significant patterns.
`sig.level`	significance level. Default is 0.95.
`sig.test`	type of significance test. If set to 0, use a regular χ^2 test. If set to 1, then perform a time-average test. If set to 2, then do a scale-average test.
`do.sig`	perform significance testing if `TRUE`. Default is `TRUE`.

Returns a biwavelet object containing:

`coi`	matrix containg cone of influence
`wave`	matrix containing the wavelet transform
`power`	matrix of power
`power.corr`	matrix of bias-corrected power using the method described by `Liu et al. (2007)`
`phase`	matrix of phases
`period`	vector of periods
`scale`	vector of scales
`dt`	length of a time step
`t`	vector of times
`xaxis`	vector of values used to plot xaxis
`s0`	smallest scale of the wavelet
`dj`	spacing between successive scales
`sigma2`	variance of time series
`mother`	mother wavelet used
`type`	type of `biwavelet` object created (`wt`)
`signif`	matrix containg significance levels

Tarik C. Gouhier (tarik.gouhier@gmail.com)

Code based on wavelet MATLAB program written by Christopher Torrence and Gibert P. Compo.

Torrence, C., and G. P. Compo. 1998. A Practical Guide to Wavelet Analysis. Bulletin of the American Meteorological Society 79:61-78.

Liu, Y., X. San Liang, and R. H. Weisberg. 2007. Rectification of the Bias in the Wavelet Power Spectrum. Journal of Atmospheric and Oceanic Technology 24:2093-2102.

t1=cbind(1:100, rnorm(100))
## Continuous wavelet transform
wt.t1=wt(t1)
## Plot power
## Make room to the right for the color bar
par(oma=c(0, 0, 0, 1), mar=c(5, 4, 4, 5) + 0.1)
plot(wt.t1, plot.cb=TRUE, plot.phase=FALSE)