py21cmfast.drivers.single_field

Compute single physical fields.

These functions are high-level wrappers around C-functions that compute 3D fields, for example initial conditions, perturbed fields and ionization fields.

Attributes

logger

Functions

brightness_temperature(*, ionized_box, perturbed_field)

Compute a coeval brightness temperature box.

compute_halo_grid(*, redshift, initial_conditions[, ...])

Compute grids of halo properties from a catalogue.

compute_initial_conditions(*, inputs)

Compute initial conditions.

compute_ionization_field(*, perturbed_field, ...[, ...])

Compute an ionized box at a given redshift.

compute_spin_temperature(*, initial_conditions, ...[, ...])

Compute spin temperature boxes at a given redshift.

compute_xray_source_field(*, initial_conditions, ...)

Compute filtered grid of SFR for use in spin temperature calculation.

determine_halo_catalog(*, redshift[, inputs, ...])

Find a halo list, given a redshift.

interp_halo_boxes(halo_boxes, fields, redshift)

Interpolate HaloBox history to the desired redshift.

perturb_field(*, redshift[, inputs])

Compute a perturbed field at a given redshift.

perturb_halo_catalog(*, initial_conditions[, inputs, ...])

Given a halo list, perturb the halos for a given redshift.

Module Contents

py21cmfast.drivers.single_field.brightness_temperature(*, ionized_box, perturbed_field, spin_temp=None)[source]

Compute a coeval brightness temperature box.

Parameters:

  • ionized_box (IonizedBox) – A pre-computed ionized box.

  • perturbed_field (PerturbedField) – A pre-computed perturbed field at the same redshift as ionized_box.

  • spin_temp (TsBox, optional) – A pre-computed spin temperature, at the same redshift as the other boxes.

Returns:

BrightnessTemp instance.

Parameters:
Return type:

py21cmfast.wrapper.outputs.BrightnessTemp

py21cmfast.drivers.single_field.compute_halo_grid(*, redshift, initial_conditions, inputs=None, halo_catalog=None, previous_spin_temp=None, previous_ionize_box=None)[source]

Compute grids of halo properties from a catalogue.

At the moment this simply produces halo masses, stellar masses and SFR on a grid of HII_DIM. In the future this will compute properties such as emissivities which will be passed directly into ionize_box etc. instead of the catalogue.

Parameters:

  • initial_conditions (InitialConditions) – The initial conditions of the run.

  • inputs (InputParameters, optional) – The input parameters specifying the run.

  • halo_catalog (HaloCatalog, optional) – This contains all the dark matter haloes obtained if using a discrete halo model. This is a list of halo masses and coordinates for the dark matter halos.

  • previous_spin_temp (TsBox, optional) – The previous spin temperature box. Used for feedback when USE_MINI_HALOS==True

  • previous_ionize_box (IonizedBox or None) – An at the last timestep. Used for feedback when USE_MINI_HALOS==True

Returns:

HaloBox – An object containing the halo box data.

Other Parameters:

regenerate, write, cache – See docs of initial_conditions() for more information.

Parameters:
Return type:

py21cmfast.wrapper.outputs.HaloBox

py21cmfast.drivers.single_field.compute_initial_conditions(*, inputs)[source]

Compute initial conditions.

Parameters:

  • inputs – The InputParameters instance defining the run.

  • regenerate (bool, optional) – Whether to force regeneration of data, even if matching cached data is found.

  • cache – An OutputCache object defining how to read cached boxes.

  • write – A boolean specifying whether we need to cache the box.

Returns:

InitialConditions

Parameters:

inputs (py21cmfast.wrapper.inputs.InputParameters)

Return type:

py21cmfast.wrapper.outputs.InitialConditions

py21cmfast.drivers.single_field.compute_ionization_field(*, perturbed_field, initial_conditions, inputs=None, previous_perturbed_field=None, previous_ionized_box=None, spin_temp=None, halobox=None)[source]

Compute an ionized box at a given redshift.

This function has various options for how the evolution of the ionization is computed (if at all). See the Notes below for details.

Parameters:

  • initial_conditions (InitialConditions instance) – The initial conditions.

  • inputs (InputParameters) – The input parameters specifying the run. Since this may be the first box to use the astro params/flags, it is needed when we have not computed a TsBox or HaloBox.

  • perturbed_field (PerturbedField) – The perturbed density field.

  • previous_perturbed_field (PerturbedField, optional) – An perturbed field at higher redshift. This is only used if USE_MINI_HALOS is included.

  • previous_ionize_box (IonizedBox or None) – An ionized box at higher redshift. This is only used if INHOMO_RECO and/or USE_TS_FLUCT are true. If either of these are true, and this is not given, then it will be assumed that this is the “first box”, i.e. that it can be populated accurately without knowing source statistics.

  • spin_temp (TsBox or None, optional) – A spin-temperature box, only required if USE_TS_FLUCT is True. If None, will try to read in a spin temp box at the current redshift, and failing that will try to automatically create one, using the previous ionized box redshift as the previous spin temperature redshift.

  • halobox (HaloBox or None, optional) – If passed, this contains all the dark matter haloes obtained if using the lagrangian source models. These are grids containing summed halo properties such as ionizing emissivity.

Returns:

IonizedBox – An object containing the ionized box data.

Parameters:
Return type:

py21cmfast.wrapper.outputs.IonizedBox

Notes

Typically, the ionization field at any redshift is dependent on the evolution of xHI up until that redshift, which necessitates providing a previous ionization field to define the current one. If neither the spin temperature field, nor inhomogeneous recombinations (specified in flag options) are used, no evolution needs to be done. If the redshift is beyond Z_HEAT_MAX, previous fields are not required either.

py21cmfast.drivers.single_field.compute_spin_temperature(*, initial_conditions, perturbed_field, inputs=None, xray_source_box=None, previous_spin_temp=None, cleanup=False)[source]

Compute spin temperature boxes at a given redshift.

See the notes below for how the spin temperature field is evolved through redshift.

Parameters:

  • initial_conditions (InitialConditions) – The initial conditions

  • inputs (InputParameters) – The input parameters specifying the run. Since this will be the first box to use the astro params/flags when SOURCE_MODEL=’E-INTEGRAL’ and USE_TS_FLUCT=True.

  • perturbed_field (PerturbedField, optional) – If given, this field will be used, otherwise it will be generated. To be generated, either initial_conditions and redshift must be given, or simulation_options, cosmo_params and redshift. By default, this will be generated at the same redshift as the spin temperature box. The redshift of perturb field is allowed to be different than redshift. If so, it will be interpolated to the correct redshift, which can provide a speedup compared to actually computing it at the desired redshift.

  • xray_source_box (XraySourceBox, optional) – When using a lagrangian source model, this box specifies the filtered sfr and xray emissivity at all redshifts/filter radii required by the spin temperature algorithm.

  • previous_spin_temp (TsBox or None) – The previous spin temperature box. Needed when we are beyond the first snapshot

Returns:

TsBox – An object containing the spin temperature box data.

Other Parameters:

regenerate, write, cache – See docs of initial_conditions() for more information.

Parameters:
Return type:

py21cmfast.wrapper.outputs.TsBox

py21cmfast.drivers.single_field.compute_xray_source_field(*, initial_conditions, hboxes, redshift)[source]

Compute filtered grid of SFR for use in spin temperature calculation.

This will filter over the halo history in annuli, computing the contribution to the SFR density

If no halo field is passed one is calculated at the desired redshift as if it is the first box.

Parameters:

  • initial_conditions (InitialConditions) – The initial conditions of the run. The user and cosmo params

  • hboxes (Sequence of HaloBox instances) – This contains the list of Halobox instances which are used to create this source field

Returns:

XraySourceBox – An object containing x ray heating, ionisation, and lyman alpha rates.

Other Parameters:

regenerate, write, cache – See docs of initial_conditions() for more information.

Parameters:
Return type:

py21cmfast.wrapper.outputs.XraySourceBox

py21cmfast.drivers.single_field.determine_halo_catalog(*, redshift, inputs=None, initial_conditions, descendant_halos=None)[source]

Find a halo list, given a redshift.

Parameters:

  • redshift (float) – The redshift at which to determine the halo list.

  • initial_conditions (InitialConditions instance) – The initial conditions fields (density, velocity).

  • descendant_halos (HaloCatalog instance, optional) – The halos that form the descendants (i.e. lower redshift) of those computed by this function. If this is not provided, we generate the initial stochastic halos directly in this function (and progenitors can then be determined by these).

Returns:

HaloCatalog

Other Parameters:

regenerate, write, cache – See docs of initial_conditions() for more information.

Parameters:
Return type:

py21cmfast.wrapper.outputs.HaloCatalog

py21cmfast.drivers.single_field.interp_halo_boxes(halo_boxes, fields, redshift)[source]

Interpolate HaloBox history to the desired redshift.

Photon conservation & Xray sources require halo boxes at redshifts that are not equal to the current redshift, and may be between redshift steps. So we need a function to interpolate between two halo boxes. We assume here that z_arr is strictly INCERASING

Parameters:

  • halo_boxes (list of HaloBox instances) – The halobox history to be interpolated

  • fields (List of Strings) – The properties of the haloboxes to be interpolated

  • redshift (float) – The desired redshift of interpolation

Returns:

HaloBox – An object containing the halo box data

Parameters:
Return type:

py21cmfast.wrapper.outputs.HaloBox

py21cmfast.drivers.single_field.perturb_field(*, redshift, inputs=None, initial_conditions)[source]

Compute a perturbed field at a given redshift.

Parameters:

  • redshift (float) – The redshift at which to compute the perturbed field.

  • initial_conditions (InitialConditions instance) – The initial conditions.

Returns:

PerturbedField

Other Parameters:

regenerate, write, cache – See docs of initial_conditions() for more information.

Parameters:
Return type:

py21cmfast.wrapper.outputs.PerturbedField

Examples

>>> initial_conditions = compute_initial_conditions()
>>> field7 = perturb_field(7.0, initial_conditions)
>>> field8 = perturb_field(8.0, initial_conditions)

The user and cosmo parameter structures are by default inferred from the initial_conditions.

py21cmfast.drivers.single_field.perturb_halo_catalog(*, initial_conditions, inputs=None, previous_spin_temp=None, previous_ionize_box=None, halo_catalog)[source]

Given a halo list, perturb the halos for a given redshift.

Parameters:

  • initial_conditions (InitialConditions) – The initial conditions of the run. The user and cosmo params as well as the random seed will be set from this object.

  • halo_catalog (:class: ~HaloCatalog) – The halo catalogue in Lagrangian space to be perturbed.

Returns:

PerturbedHaloCatalog

Other Parameters:

regenerate, write, direc – See docs of initial_conditions() for more information.

Parameters:
Return type:

py21cmfast.wrapper.outputs.PerturbedHaloCatalog

Examples

Fill this in once finalised

py21cmfast.drivers.single_field.logger[source]