lib.catalog.utils.DistanceToRedshift

class lib.catalog.utils.DistanceToRedshift(distance, zmax=100.0, nz=2048, interp_order=3)

Bases: object

Class that holds a conversion distance -> redshift.

Initialize DistanceToRedshift. Creates an array of redshift -> distance in log(redshift) and instantiates a spline interpolator distance -> redshift.

Parameters

  • distance (callable) – Callable that provides distance as a function of redshift (array).

  • zmax (float, default=100.) – Maximum redshift for redshift <-> distance mapping.

  • nz (int, default=2048) – Number of points for redshift <-> distance mapping.

  • interp_order (int, default=3) – Interpolation order, e.g. 1 for linear interpolation, 3 for cubic splines.

Methods

__call__(distance)

Return (interpolated) redshift at distance distance (scalar or array).