- chaosmagpy.coordinate_utils.synth_rotate_gauss(time, frequency, spectrum, scaled=None)¶
Compute time-dependent matrices that transform spherical harmonic expansion from the given Fourier coefficients.
The function computes matrices that transform the spherical harmonic expansion of a time-dependent reference system (e.g. GSM, SM) to GEO using Fourier expansion of the transformation coefficients.
- timendarray, shape (…)
Time given as modified Julian date, i.e. with respect to the date 0h00 January 1, 2000 (mjd2000).
- frequencyndarray, shape (k,) or (k, m, n)
Vector of positive frequencies given in oscillations per day.
- spectrumndarray, shape (k, m, n)
Fourier components of the matrices (reside in the last two dimensions).
- scaledbool, optional (defaults to
True, the function expects scaled Fourier coefficients, i.e. the non-bias term (all non-zero frequency terms) have been multiplied by a factor of 2. Hence, taking the real part of the spectrum multiplied with the complex exponentials results in the correctly scaled and time-shifted real-valued harmonics.
- matrixndarray, shape (…, m, n)