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Extract a signal/cycle from a wavelet spectra using a set period and boundaries

Source: R/extract_signal_stable.R
extract_signal_stable.Rd

Extracts a cycle from the wavelet object created using the analyse_wavelet function using a fixed period and fixed period boundaries defined as factors of the original cycle

Usage

extract_signal_stable(
  wavelet = NULL,
  cycle = NULL,
  period_up = 1.2,
  period_down = 0.8,
  add_mean = TRUE,
  plot_residual = FALSE,
  keep_editable = FALSE
)

Arguments

wavelet

Wavelet object (list) created with analyse_wavelet; the signal is reconstructed from its coefficients. Required (Default=NULL).

cycle

Constant period of the cycle to extract, in the depth/time unit of the wavelet (numeric, > 0). Required (Default=NULL).

period_up

Upper boundary of the band that is reconstructed, as a factor of cycle (numeric, > period_down). Default=1.2.

period_down

Lower boundary of the band that is reconstructed, as a factor of cycle (numeric, > 0). Default=0.8.

add_mean

Add the mean of the original data series to the extracted cycle (logical, TRUE or FALSE); FALSE returns it centred on zero. Default=TRUE.

plot_residual

Plot the residual (extracted cycle minus data) against depth/time and its histogram (logical, TRUE or FALSE). Default=FALSE.

keep_editable

Keep the plot layout active after the call so that extra features can be added to the residual plot (logical, TRUE or FALSE); FALSE restores the previous graphical parameters. Only used when plot_residual=TRUE. Default=FALSE.

Value

#'Returns a matrix with 2 columns. The first column is time/depth. The second column is the extracted signal/cycle.

References

Angi Roesch and Harald Schmidbauer (2018). WaveletComp: Computational Wavelet Analysis. R package version 1.1. https://CRAN.R-project.org/package=WaveletComp

Gouhier TC, Grinsted A, Simko V (2021). R package biwavelet: Conduct Univariate and Bivariate Wavelet Analyses. (Version 0.20.21), https://github.com/tgouhier/biwavelet

Torrence, C., and G. P. Compo. 1998. A Practical Guide to Wavelet Analysis. Bulletin of the American Meteorological Society 79:61-78. https://paos.colorado.edu/research/wavelets/bams_79_01_0061.pdf

Author

Code based on the reconstruct function of the 'WaveletComp' R package which is based on the wavelet 'MATLAB' code written by Christopher Torrence and Gibert P. Compo (1998).

Examples

#Example in which the ~210yr de Vries cycle is extracted from the Total Solar
#Irradiance data set of Steinhilber et al., (2012)

#Perform the CWT
TSI_wt <-
analyse_wavelet(
data = TSI,
dj = 1/200,
lowerPeriod = 16,
upperPeriod = 8192,
   verbose = FALSE,
   omega_nr = 6
 )

#Extract the 210 yr de Vries cycle from the wavelet spectra
de_Vries_cycle <- extract_signal_stable(wavelet=TSI_wt,
cycle=210,
period_up =1.25,
period_down = 0.75,
add_mean=TRUE,
plot_residual=FALSE,
keep_editable=FALSE)