WrapSpectralResults: Wrap spectral results for several data sets

In EarthSystemDiagnostics/proxysnr: Separate Signal and Noise in Climate Proxy Records

Description

This wrapper function is used to combine all main spectral results for the signal, noise and signal-to-noise ratio as presented and discussed in Münch and Laepple (2018), but it can also be used to combine the results for other data sets.

Usage

WrapSpectralResults(
  ...,
  diffusion = NULL,
  time.uncertainty = NULL,
  df.log = 0.05,
  crit.diffusion = 2,
  inverse.tf = FALSE
)

Arguments

...	a comma separated list of named proxy data sets to analyse.
diffusion	a list of (inverse) transfer functions to correct for the effect of diffusion. The length of the list has to match the number of provided data sets, thus, one transfer function per data set is assumed. If NULL, no diffusion correction is applied. If you want to omit the diffusion correction only for some specific data set(s), set the corresponding list element(s) to NA.
time.uncertainty	similar to diffusion a list of (inverse) transfer functions to correct for the effect of time uncertainty.
df.log	a vector of Gaussian kernel widths in log space to smooth the spectral estimates from each data set. If dimensions do not fit, its length is recycled to match the number of data sets.
crit.diffusion	maximum diffusion correction value to obtain cutoff frequencies until which results are analysed to avoid large uncertainties at the high-frequency end of the spectra.
inverse.tf	logical; if TRUE, it is assumed that diffusion and time.uncertainty provide the inverse transfer functions which can be readily used to correct the spectra. If FALSE (the default), the inverse of the provided transfer functions is calculated within the function and used for the corrections. See Eqs. (4) in Münch and Laepple (2018) for the definitions.

Value

A list of N lists, where N is the number of provided data sets and where each of these lists contains up to five elements:

f.cutoff:

a two-element vector with the index and value of the cutoff frequency.

raw:

a list with three objects of class "spec": the raw signal, noise and corresponding SNR spectra.

corr.diff.only:

a list with three objects of class "spec": the signal, noise and corresponding SNR spectra after correction only for the effect of diffusion.

corr.t.unc.only:

a list with three objects of class "spec": the signal, noise and corresponding SNR spectra after correction only for the effect of time uncertainty.

corr.full:

a list with three objects of class "spec": the signal, noise and corresponding SRN spectra after correction for both the effects of diffusion and time uncertainty.

The number of the returned list elements for each data set depends on whether transfer functions for the corrections have been provided in diffusion and time.uncertainty or not.

Author(s)

Thomas Münch

References

Münch, T. and Laepple, T.: What climate signal is contained in decadal- to centennial-scale isotope variations from Antarctic ice cores? Clim. Past, 14, 2053–2070, https://doi.org/10.5194/cp-14-2053-2018, 2018.

Examples

# Get main results of Münch and Laepple (2018)

results <- WrapSpectralResults(
               dml1 = dml$dml1, dml2 = dml$dml2, wais = wais,
               diffusion = diffusion.tf,
               time.uncertainty = time.uncertainty.tf,
               df.log = c(0.15, 0.15, 0.1))

EarthSystemDiagnostics/proxysnr documentation built on Oct. 2, 2021, 3:03 p.m.