Classes for spherical harmonic coefficients.

## Subclasses

Subclass name Description
SHRealCoeffs Real spherical harmonic coefficients class.
SHComplexCoeffs Complex spherical harmonic coefficients class.

## Initialization

Initialization method Description
x = SHCoeffs.from_array() Initialize using coefficients from an array.
x = SHCoeffs.from_random() Initialize using random coefficients with a prescribed power spectrum.
x = SHCoeffs.from_zeros() Initialize with coefficients set to zero.
x = SHCoeffs.from_file() Initialize using coefficients from a file.
x = SHCoeffs.from_netcdf() Initialize using coefficients from a netcdf file.
x = SHCoeffs.from_cap() Initialize using coefficients of a spherical cap.

## Class attributes

Attribute Description
lmax The maximum spherical harmonic degree of the coefficients.
coeffs The raw coefficients with the specified normalization and phase conventions.
errors The uncertainties of the spherical harmonic coefficients.
error_kind An arbitrary string describing the kind of errors, such as None, 'unspecified', 'calibrated' or 'formal'.
normalization The normalization of the coefficients: '4pi', 'ortho', 'schmidt', or 'unnorm'.
csphase Defines whether the Condon-Shortley phase is used (1) or not (-1).
mask A boolean mask that is True for the permissible values of degree l and order m.
kind The coefficient data type: either 'complex' or 'real'.
units The units of the spherical harmonic coefficients.
header A list of values from the header line of the input file used to initialize the class.
header2 A list of values from the second header line of the input file used to initialize the class.

## Class methods

Method Description
degrees() Return an array listing the spherical harmonic degrees from 0 to lmax.
spectrum() Return the spectrum of the function.
cross_spectrum() Return the cross-spectrum of two functions.
admittance() Return the admittance with another function.
correlation() Return the spectral correlation with another function.
admitcorr() Return the admittance and spectral correlation with another function.
volume() Calculate the volume of the body.
centroid() Calculate the centroid of the body.
set_coeffs() Set coefficients in-place to specified values.
rotate() Rotate the coordinate system used to express the spherical harmonics coefficients and return a new class instance.
convert() Return a new class instance using a different normalization convention.
pad() Return a new class instance that is zero padded or truncated to a different lmax.
expand() Evaluate the coefficients either on a spherical grid and return an SHGrid class instance, or for a list of latitude and longitude coordinates.
gradient() Compute the horizontal gradient of the function and return an SHGradient class instance.
plot_spectrum() Plot the spectrum as a function of spherical harmonic degree.
plot_cross_spectrum() Plot the cross-spectrum of two functions.
plot_spectrum2d() Plot the spectrum of all spherical-harmonic coefficients.
plot_cross_spectrum2d() Plot the cross-spectrum of all spherical-harmonic coefficients.
plot_admittance() Plot the admittance with another function.
plot_correlation() Plot the correlation with another function.
plot_admitcorr() Plot the admittance and/or correlation with another function.
to_array() Return an array of spherical harmonics coefficients with a different normalization convention.
to_file() Save raw spherical harmonic coefficients to a text or binary file.
to_netcdf() Return the coefficient data as a netcdf formatted file or object.
copy() Return a copy of the class instance.
info() Print a summary of the data stored in the SHCoeffs instance.