The domains module : handle computation domain

---

Module domains provides three main objects:

• Subdomain : dataclass for subdivisions of the computational domain

• Obstacle : Subdomain subclass with custom boundary possibilities

• Domain : Container for Subdomain objects

---

class fdgrid.domains.Domain(shape, data=None)

Bases: object

Set of Subdomain objects.

Parameters

• shape (Size of the domain. Must be a 2 elements tuple) –

• data (list of Subdomain objects or coordinates) –

append(val, key=None)

Append ‘val’ to the Domain object.

Parameters

• val (The object to add to the instance.) – Must be a Subdomain object or a list/tuple of Subdomain objects

• key (new key for val) –

autojoin(include_split=False)

Automatically join domains that can be joined.

copy()

Create copy of the instance.

static isjoinable(sub1, sub2, include_split=False)

Check if sub1 and sub2 can be joined.

property ix

Return list of x coordinates.

property iz

Return list of z coordinates.

join(key1, key2, include_split=False, tag=None)

Join key1 and key2 Subdomain objects.

keys()

Return all keys of Domain instance.

mask()

Create mask array of the domain.

periodic_bc(mask, axis)

Arange subdomains to take into account periodic boundary condtions.

pop(n)

Remove value of index n from the Domain object.

reset_keys()

Reset all keys then attribute new ordered keys.

property rx

Return list of ranges (over Subdomain x coordinates).

property rz

Return list of ranges (over Subdomain z coordinates).

show(legend=False, fcolor='b', ecolor='y')

Represent the Subdomains.

sort(inplace=False)

Sort domains.

If inplace is True, Domain is sorted inplace. If inplace is False, return a new instance.

split(key, index, nbc=None, axis=None)

Split ‘key’ subdomain.

Parameters

• index (int|tuple|list) –

• nbc (Only if index is a sequence. New bc for the domain defined by 'index') –

• axis (0 or 1. Along which axis to split) –

steal(other, key, newkey=None)

Steal key from other.

property sx

Return list of slices (over Subdomain x coordinates).

property sz

Return list of slices (over Subdomain z coordinates).

property xz

Return list of coordinates.

class fdgrid.domains.Obstacle(xz: tuple, bc: str = '....', key: str = '', axis: int = - 1, tag: str = '')

Bases: fdgrid.domains.Subdomain

Obstacle object.

Parameters

• xz (Coordinates of the Subdomain : left, bottom, right, top) –

• bc (Boundary conditions. Must be a string of 4 characters among 'W|Z|V') –

• key (Key of the subdomain. Optional) –

• axis (0 or 1. The direction of the subdomain if relevant. Optional.) –

• tag (str. The type of Subdomain. Optional) –

make_moving_bc(x, z, LOG=False)

Construct moving boundaries.

set_moving_bc(*args)

Set parameters for moving bc. For each moving bc of the obstacle, you can specify the parameters as a dictionnary containing the following optional keys :

Parameters

• f (float, str) – frequency of the normal velocity.

• A (float) – Amplitude of the normal velocity

• phi (float) – Phase of the normal velocity

• profile ({'sine', 'tukey'}) – Function for normal velocity profile construction

• kwargs (dict) – optional arguments for profile

Note

profile argument can be:

• ‘sine’ : sinus profile. kw: n - wavelength (default: 2 for half period)

• ‘tukey’ : tapered cosine profile. kw: alpha - edge width (default: 0)

Examples

>>> obs1 = Obstacle([10, 10, 100, 100], 'VVWV')

>>> obs1.set_moving_bc({'f': 100, 'A': 2.1, 'profile': 'sine'},
                       {'f': 500, 'A': -1.5, 'profile': 'tukey'},
                       {'f': 500, 'A': 1.5 'profile': 'tukey', 'kwargs':{'alpha': 0.4}})

static sine(c, sc, **kwargs)

Sine profile.

static tukey(_, sc, **kwargs)

Tapered cosine profile.

class fdgrid.domains.Subdomain(xz: tuple, bc: str = '....', key: str = '', axis: int = - 1, tag: str = '')

Bases: object

Subdivision of the computation domain.

Parameters

• xz (list) – Coordinates of the Subdomain : left, bottom, right, top

• bc (str) – Boundary conditions. Must be a string of 4 characters among ‘A|W|Z|P|R’

• key (int, optional) – Key of the subdomain.

• axis ({0, 1}, optional) – The direction of the subdomain if relevant.

• tag (str, optional) – The type of Subdomain.

property axname

Returns “x” or “z” whether axis is 0 or 1. Return 2 if both.

property center

Returns the center of the Subdomain.

intersection(other)

Return common border with another object.

split(index, nbc=None, axis=None)

Split the subdomain into several new subdomains.

If index is integer, split into two Subdomain objects at ‘index’. If index is tuple/list (len(index) must be 2), split into 3 (or less) Subdomain objects.

Parameters

• index ({int, tuple, list}) – Where to split the subdomain

• nbc (str) – Only if index is a sequence. New bc for the domain defined by ‘index’

• axis ({0, 1}) – Along which axis to split

touch(other)

Return borders that touch the domain.