pynbody.analysis.cosmology.redshift#
- pynbody.analysis.cosmology.redshift(f, time)[source]#
Calculate the redshift given a snapshot and a time since Big Bang in Gyr.
Uses scipy.optimize.newton to do the root finding if number of elements in the time array is less than 1000; otherwise uses a linear interpolation.
- Parameters:
f (SimSnap) – The snapshot from which to obtain the cosmological parameters.
time (float, list, or np.ndarray) – The time(s) since the Big Bang at which to calculate the redshift.
- Returns:
The redshift(s) corresponding to the input time(s).
- Return type:
float or np.ndarray