halomod.tools.power_to_corr_ogata

halomod.tools.power_to_corr_ogata(power: ndarray, k: ndarray, r: ndarray, h=0.005, power_pos=(True, True), rtol=0.001, atol=1e-15, _reverse=False)[source]

Convert a 3D power spectrum to a correlation function.

Uses Ogata’s method (Ogata 2005) for Hankel Transforms in 3D.

Parameters:

  • power (np.ndarray) – The power spectrum to convert – either 1D or 2D. If 1D, it is the power as a function of k. If 2D, the first dimension should be len(r), and the power to integrate is considered to be different for each r.

  • k (np.ndarray) – Array of same length as the last axis of power, giving the fourier-space co-ordinates.

  • r (np.ndarray) – The real-space co-ordinates to which to transform.

  • h (int, optional) – Controls the spacing of the intervals (note the intervals are not equispaced). Smaller numbers give smaller intervals.

  • power_pos (tuple of bool, optional) – Whether ‘power’ is definitely positive, at either end. If so, a slightly better extrapolation can be achieved.

Notes

See the hankel documentation for details on the implementation here. This particular function is restricted to a spherical transform.