View source: R/StackCorrelation.R
StackCorrelation | R Documentation |
This function calculates the theoretical correlation of a "stacked"
proxy record with the common signal depending on the number of records in
the stack and the time resolution of the records, given estimates of the
average proxy signal and noise spectra.
StackCorrelation(
input,
N = 1,
f1 = 2,
f2 = "max",
freq.cut.lower = NULL,
freq.cut.upper = NULL
)
input |
a list of the spectral objects lists |
N |
integer vector with the number of records in the assumed stack;
correlations are then calculated for stacks with record numbers according to
each element of |
f1 |
index of the the minimum frequency from which to integrate the signal and noise spectra for calculating the correlation; per default the lowest frequency of the spectral estimates is omitted |
f2 |
index of the maximum frequency until which to integrate the signal and noise spectra for calculating the correlation; defaults to use the maximum frequency of the given spectral estimates |
freq.cut.lower |
lower frequency (not index!) at which to cut the
spectra: this provides a direct way for specifying a minimum frequency for
the integration different from the minimum frequency of the spectral
estimates. Setting |
freq.cut.upper |
upper frequency (not index!) at which to cut the
spectra: this provides a direct way for specifying a maximum frequency for
the integration different from the maximum frequency of the spectral
estimates. Setting |
The function is an implementation of Eqs. (6) and (7) in Münch and Laepple
(2018). The integral in (6) is approximated by the cumulative sum of the
integration arguments from f.int1
to f.int2
, where
f.int1 = f1
and f.int2
consecutively increases from f1
to f2
.
a list of two components:
numeric vector of frequencies corresponding to the upper ends of the cumulative integrations
a n * m
matrix where n
corresponds to
length(N)
and m
is given by length(freq)
providing
the correlation values as a function of the number of averaged records and
the record resolution (= increasing upper frequency of the integration)
Thomas Münch
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.
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