astronomix.initial_condition_generation.turbulent_ic_generator module

astronomix.initial_condition_generation.turbulent_ic_generator module#

Generate Gaussian random fields with a prescribed power-law spectrum.

Builds a real-valued 3D turbulent field by sampling complex Fourier coefficients with a target amplitude scaling A0 * k^slope inside a wavenumber band, enforcing Hermitian symmetry so the inverse transform is real, and transforming back to real space. The implementation deliberately avoids explicit meshgrid / index arrays (relying on broadcasting and roll / flip tricks instead) to keep the memory footprint low at large resolution.

astronomix.initial_condition_generation.turbulent_ic_generator.create_turb_field(Ndim, A0, slope, kmin, kmax, key, sharding=None, kroll_frac=0.85, zero_mean=True)[source]#

Generate a real Gaussian random field with a target amplitude scaling.

This version is optimized for memory by avoiding explicit meshgrid / index arrays and using broadcasting and efficient array manipulations instead.

Parameters:

  • Ndim – The number of grid points along each of the three axes.

  • A0 – The amplitude prefactor of the power-law spectrum.

  • slope – The spectral slope (amplitude ~ A0 * k^slope).

  • kmin – The lower edge of the wavenumber band carrying power.

  • kmax – The upper edge of the wavenumber band carrying power.

  • key – The PRNG key used to sample the Fourier coefficients.

  • sharding – An optional sharding applied to the large k-space arrays.

  • kroll_frac – The fraction of kmax at which the cosine roll-off begins.

  • zero_mean – Whether to remove the DC component so the field has zero mean.

Returns:

The real-valued turbulent field of shape (Ndim, Ndim, Ndim).

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