HOME | DOWNLOAD | DOCUMENTATION | FAQ |
> Home > Documentation > Python > Global and Localized Spectral Analysis
SHAdmitCorr
Calculate the admittance and correlation spectra of two real functions.
Usage
admit
, error
, corr
= SHAdmitCorr (gilm
, tilm
, [lmax
])
Returns
admit
: float, dimension (lmax
+1)- The admittance function, which is equal to
Sgt/Stt
. error
: float, dimension (lmax
+1)- The uncertainty of the admittance function, assuming that
gilm
andtilm
are related by a linear isotropic transfer function, and that the lack of correlation is a result of uncorrelated noise. corr
: float, dimension (lmax
+1)- The degree correlation function, which is equal to
Sgt/sqrt(Sgg Stt)
.
Parameters
gilm
: float, dimension (2,lmaxg
+1,lmaxg
+1)- The real spherical harmonic coefficients of the function
G
. tilm
: float, dimension (2,lmaxt
+1,lmaxt
+1)- The real spherical harmonic coefficients of the function
T
. lmax
: optional, integer, default = min(lmaxg
,lmaxt
)- The maximum spherical harmonic degree that will be calculated for the admittance and correlation spectra. This must be less than or equal to the minimum of
lmaxg
andlmaxt
.
Description
SHAdmitCorr
will calculate the admittance, admittance error, and correlation spectra associated with two real functions expressed in real spherical harmonics. The admittance is defined as Sgt/Stt
, where Sgt
is the cross-power spectrum of two functions G
and T
. The degree-correlation spectrum is defined as Sgt/sqrt(Sgg Stt)
, which can possess values between -1 and 1. The error of the admittance is calculated assuming that G
and T
are related by a linear isotropic transfer function:Gilm = Ql Tilm + Nilm
, where N
is noise that is uncorrelated with the topography. It is important to note that the relationship between two fields is often not described by such an isotropic expression.
See also
> Home > Documentation > Python > Global and Localized Spectral Analysis
Laboratoire Lagrange | Observatoire de la Côte d'Azur | © 2016 SHTOOLS |