## Real spectral analysis

Routine name Description
SHPowerL Compute the power of a real function for a single spherical harmonic degree.
SHPowerDensityL Compute the power spectral density of a function for a single spherical harmonic degree.
SHCrossPowerL Compute the cross-power of two functions for a single spherical harmonic degree.
SHCrossPowerDensityL Compute the cross-power spectral density of two functions for a single spherical harmonic degree.
SHPowerSpectrum Compute the power spectrum of a function.
SHPowerSpectrumDensity Compute the power spectral density of a function.
SHCrossPowerSpectrum Compute the cross-power spectrum of two functions.
SHCrossPowerSpectrumDensity Compute the cross-power spectral density of two functions.