py21cmfast.CosmoParams¶

class py21cmfast.CosmoParams¶

Bases: InputStruct

Cosmological parameters (with defaults) which translates to a C struct.

To see default values for each parameter, use CosmoParams._defaults_. All parameters passed in the constructor are also saved as instance attributes which should be considered read-only. This is true of all input-parameter classes.

Default parameters are based on Plank18, https://arxiv.org/pdf/1807.06209.pdf, Table 2, last column. [TT,TE,EE+lowE+lensing+BAO]

Parameters:

SIGMA_8 (float, optional) – RMS mass variance (power spectrum normalisation).
hlittle (float, optional) – The hubble parameter, H_0/100.
OMm (float, optional) – Omega matter.
OMb (float, optional) – Omega baryon, the baryon component.
POWER_INDEX (float, optional) – Spectral index of the power spectrum.
A_s (float, optional) – Amplitude of primordial curvature power spectrum, at k_pivot = 0.05 Mpc^-1.

classmethod __init_subclass__()¶

Store each subclass for easy access.

Return type:: None

__str__()¶

Human-readable string representation of the object.

Return type:: str

asdict()¶

Return a dict representation of the instance.

Examples

This dict is such that doing the following should work, i.e. it can be used exactly to construct a new instance of the same object:

>>> inp = InputStruct(**params)
>>> newinp =InputStruct(**inp.asdict())
>>> inp == newinp

Return type:: dict

clone(**kwargs)¶: Make a fresh copy of the instance with arbitrary parameters updated.

classmethod from_astropy(cosmo, **kwargs)¶

Create a CosmoParams object from an astropy cosmology object.

Pass SIGMA_8 and POWER_INDEX as kwargs if you want to override the default values.

Parameters:: cosmo (astropy.cosmology.FLRW)

classmethod from_subdict(dct, safe=True)¶: Construct an instance of a parameter structure from a dictionary.

classmethod new(x=None, **kwargs)¶

Create a new instance of the struct.

Parameters:

x (dict | InputStruct | None) – Initial values for the struct. If x is a dictionary, it should map field names to their corresponding values. If x is an instance of this class, its attributes will be used as initial values. If x is None, the struct will be initialised with default values.

Other Parameters:

All other parameters should be passed as if directly to the class constructor
(i.e. as parameter names).

Parameters:

x (dict | Self | None)

Examples

>>> up = SimulationOptions({'HII_DIM': 250})
>>> up.HII_DIM
250
>>> up = SimulationOptions(up)
>>> up.HII_DIM
250
>>> up = SimulationOptions()
>>> up.HII_DIM
200
>>> up = SimulationOptions(HII_DIM=256)
>>> up.HII_DIM
256

property A_s: float¶

Amplitude of primordial curvature power spectrum, at k_pivot = 0.05 Mpc^-1.

If not given explicitly, it is auto-calculated via sigma_8 and the other cosmological parameters.

Return type:: float

OMb: float¶

OMk: float¶

property OMl¶: Omega lambda, dark energy density.

OMm: float¶

OMn: float¶

OMr: float¶

OMtot: float¶

POWER_INDEX: float¶

property SIGMA_8: float¶

RMS mass variance (power spectrum normalisation).

If not given explicitly, it is auto-calculated via A_s and the other cosmological parameters.

Return type:: float

Y_He: float¶

property cdict: dict¶

A python dictionary containing the properties of the wrapped C-struct.

The memory pointed to by this dictionary is not owned by the wrapped C-struct, but is rather just a python dict. However, in contrast to asdict(), this method transforms the properties to what they should be in C (e.g. linear space vs. log-space) before putting them into the dict.

This dict also contains only the properties of the wrapped C-struct, rather than all properties of the InputStruct instance (some attributes of the python instance are there only to guide setting of defaults, and don’t appear in the C-struct at all).

Return type:: dict

property cosmo¶: An astropy cosmology object for this cosmology.

property cstruct: py21cmfast.wrapper.structs.StructWrapper¶

The object pointing to the memory accessed by C-code for this struct.

Return type:: py21cmfast.wrapper.structs.StructWrapper

hlittle: float¶

property struct: py21cmfast.wrapper.structs.StructWrapper¶

The python-wrapped struct associated with this input object.

Return type:: py21cmfast.wrapper.structs.StructWrapper

wl: float¶