@@ -24,7 +24,7 @@ Comments can be inserted anywhere and start with a hash:

.. code:: YAML

# Description of the physics

# Descrption of the physics

viscosity_alpha: 2.0

dt_max: 1.5 # seconds

...

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@@ -113,7 +113,7 @@ schemes that make use of the unit of electric current. There is also

no incentive to use anything else than Kelvin but that makes the whole

system consistent with any possible unit system.

If one is interested in using the more humorous `FFF unit

If one is interested in using the more humourous `FFF unit

system <https://en.wikipedia.org/wiki/FFF_system>`_ one would use

.. code:: YAML

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@@ -133,8 +133,8 @@ Cosmology

---------

When running a cosmological simulation, the section ``Cosmology`` sets the values of the

cosmological model. The expanded :math:`\Lambda\rm{CDM}` parameters governing the

background evolution of the Universe need to be specified here. These are:

cosmological model. The epanded :math:`\Lambda\rm{CDM}` parameters governing the

background evolution of the Univese need to be specified here. These are:

* The reduced Hubble constant: :math:`h`: ``h``,

* The matter density parameter :math:`\Omega_m`: ``Omega_m``,

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@@ -146,7 +146,7 @@ The last parameter can be omitted and will default to :math:`\Omega_r = 0`. Note

that SWIFT will verify on start-up that the matter content of the initial conditions

matches the cosmology specified in this section.

This section also specifies the start and end of the simulation expressed in

This section als specifies the start and end of the simulation expressed in

terms of scale-factors. The two parameters are:

* Initial scale-factor: ``a_begin``,

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@@ -157,7 +157,7 @@ state of dark energy :math:`w(a)`. We use the evolution law :math:`w(a) =

w_0 + w_a (1 - a)`. The two parameters in the YAML file are:

* The :math:`z=0` dark energy equation of state parameter :math:`w_0`: ``w_0``

* The dark energy equation of state evolution parameter :math:`w_a`: ``w_a``

* The dark energy equation of state evolutio parameter :math:`w_a`: ``w_a``

If unspecified these parameters default to the default

:math:`\Lambda\rm{CDM}` values of :math:`w_0 = -1` and :math:`w_a = 0`.

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@@ -179,13 +179,13 @@ use the following parameters:

w_0: -1.0 # (Optional)

w_a: 0. # (Optional)

When running a non-cosmological simulation (i.e. without the ``-c`` runtime

When running a non-cosmological simulation (i.e. without the ``-c`` runtime

flag) this section of the YAML file is entirely ignored.

Gravity

-------

The behaviour of the self-gravity solver can be modified by the parameters

The behaviour of the self-gravity solver can be modifed by the parameters

provided in the ``Gravity`` section. The theory document puts these parameters into the

context of the equations being solved. We give a brief overview here.

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@@ -206,7 +206,7 @@ The last tree-related parameter is

* The tree rebuild frequency: ``rebuild_frequency``.

The tree rebuild frequency is an optional parameter defaulting to

Thqe tree rebuild frequency is an optional parameter defaulting to

:math:`0.01`. It is used to trigger the re-construction of the tree every time a

fraction of the particles have been integrated (kicked) forward in time.

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@@ -219,12 +219,12 @@ Particle-Mesh part of the calculation. The last three are optional:

* The scale above which the short-range forces are assumed to be 0 (in units of

the mesh cell-size multiplied by :math:`a_{\rm smooth}`) :math:`r_{\rm

cut,max}`: ``r_cut_max`` (default: ``4.5``),

* The scale below which the short-range forces are assumed to be exactly Newtonian (in units of

* The scale bewlo which the short-range forces are assumed to be exactly Newtonian (in units of

the mesh cell-size multiplied by :math:`a_{\rm smooth}`) :math:`r_{\rm

cut,min}`: ``r_cut_min`` (default: ``0.1``),

For most runs, the default values can be used. Only the number of cells along

each axis needs to be specified. The remaining three values are best described

each axis needs to be sepcified. The remaining three values are best described

in the context of the full set of equations in the theory documents.

As a summary, here are the values used for the EAGLE :math:`100^3~{\rm Mpc}^3`

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@@ -308,7 +308,7 @@ Whilst for a cosmological run, one would need:

Initial Conditions

------------------

This ``InitialConditions`` section of the parameter file contains all the options related to

This ``IntialConditions`` section of the parameter file contains all the options related to

the initial conditions. The main two parameters are

* The name of the initial conditions file: ``file_name``,

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@@ -410,15 +410,15 @@ this mechanism is driven by the options in the ``Restarts`` section of the YAML

parameter file. All the parameters are optional but default to values that

ensure a reasonable behaviour.

* Whether or not to enable the dump of restart files: ``enable`` (default:

* Wether or not to enable the dump of restart files: ``enable`` (default:

``1``).

This parameter acts a master-switch for the check-pointing capabilities. All the

other options require the ``enable`` parameter to be set to ``1``.

* Whether or not to save a copy of the previous set of check-pointing files:

* Wether or not to save a copy of the previous set of check-pointing files:

``save`` (default: ``1``),

* Whether or not to dump a set of restart file on regular exit: ``onexit``

* Wether or not to dump a set of restart file on regular exit: ``onexit``

(default: ``0``),

* The wall-clock time in hours between two sets of restart files:

``delta_hours`` (default: ``6.0``).

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@@ -433,7 +433,7 @@ smaller value to allow for enough time to safely dump the check-point files.

If the directory does not exist, SWIFT will create it. When resuming a run,

SWIFT, will look for files with the name provided in the sub-directory specified

here. The files themselves are named ``basename_000001.rst`` where the basename

here. The files themselves are named ``basename_000001.rst`` where the basenme

is replaced by the user-specified name and the 6-digits number corresponds to

the MPI-rank. SWIFT writes one file per MPI rank. If the ``save`` option has

been activated, the previous set of restart files will be named

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@@ -490,7 +490,7 @@ Scheduler

Domain Decomposition

--------------------

.. [#f1] The thorough reader (or overly keen SWIFT tester) would find that the speed of light is :math:`c=1.8026\times10^{12}\,\rm{fur}\,\rm{ftn}^{-1}`, Newton's constant becomes :math:`G_N=4.896735\times10^{-4}~\rm{fur}^3\,\rm{fir}^{-1}\,\rm{ftn}^{-2}` and Planck's constant turns into :math:`h=4.851453\times 10^{-34}~\rm{fur}^2\,\rm{fir}\,\rm{ftn}^{-1}`.

.. [#f1] The thorough reader (or overly keen SWIFT tester) would find that the speed of light is :math:`c=1.8026\times10^{12}\,\rm{fur}\,\rm{ftn}^{-1}`, Newton's contant becomes :math:`G_N=4.896735\times10^{-4}~\rm{fur}^3\,\rm{fir}^{-1}\,\rm{ftn}^{-2}` and Planck's constant turns into :math:`h=4.851453\times 10^{-34}~\rm{fur}^2\,\rm{fir}\,\rm{ftn}^{-1}`.

.. [#f2] which would translate into a constant :math:`G_N=1.5517771\times10^{-9}~cm^{3}\,g^{-1}\,s^{-2}` if expressed in the CGS system.