The Topology (xentica.core.topology)¶
This package helps you build the topology for CA models.
All xentica.core.CellularAutomaton
subclasses must have
Topology
class declared inside. This class describes:
dimensions
: the number of dimensions your CA model operates on.lattice
: the type of lattice of your CA board. Builtin lattice types are available inxentica.core.topology.lattice
module.neighborhood
: the type of neighborhood for a single cell. Builtin neighborhood types are available inxentica.core.topology.neighborhood
module.border
: the type of border effect, e.g. how to process offboard cells. Builtin border types are available inxentica.core.topology.border
module.
In example, you can declare the topology for a 2dimensional orthogonal lattice with Moore neighborhood, wrapped to a 3torus, as follows:
class Topology:
dimensions = 2
lattice = core.OrthogonalLattice()
neighborhood = core.MooreNeighborhood()
border = core.TorusBorder()
Lattice (xentica.core.topology.lattice)¶
The collection of classes describing different lattice topologies.
All classes there are intended to be used inside Topology
for
lattice
class variable definition. They are also available via
xentica.core
shortcut. The example:
from xentica.core import CellularAutomaton, OrthogonalLattice
class MyCA(CellularAutomaton):
class Topology:
lattice = OrthogonalLattice()
# ...
# ...

class
xentica.core.topology.lattice.
Lattice
¶ Bases:
xentica.core.topology.mixins.DimensionsMixin
,xentica.core.mixins.BscaDetectorMixin
Base class for all lattices.
For correct behavior, lattice classes should be inherited from this class. You should also implement the following functions:
See the detailed description below.

coord_to_index_code
(coord_prefix)¶ Generate C code for obtaining cell’s index by coordinates.
This is an abstract method, you must implement it in
Lattice
subclasses.Parameters: coord_prefix – The prefix for variables, containing coordinates. Returns: A string with C code calculating cell’s index. No assignment, only a valid expression needed.

index_to_coord
(idx, bsca)¶ Obtain cell’s coordinates by its index, in pure Python.
This is an abstract method, you must implement it in
Lattice
subclasses.Parameters:  idx – Cell’s index, a positive integer, or NumPy array of indices.
 bsca –
xentica.core.CellularAutomaton
instance, to access field size and number of dimensions.
Returns: Tuple of integer coordinates, or NumPy arrays of coords per each axis.

index_to_coord_code
(index_name, coord_prefix)¶ Generate C code to obtain coordinates by cell’s index.
This is an abstract method, you must implement it in
Lattice
subclasses.Parameters:  index_name – The name of variable containing cell’s index.
 coord_prefix – The prefix for resulting variables, containing coordinates.
Returns: A string with C code, doing all necessary to process index variable and store coordinates to variables with given prefix.

is_off_board_code
(coord_prefix)¶ Generate C code to test if the cell’s coordinates are off board.
This is an abstract method, you must implement it in
Lattice
subclasses.Parameters: coord_prefix – The prefix for variables, containing coordinates. Returns: A string with C code testing coordinate variables. No assignment, only a valid expression with boolean result needed.

width_prefix
= '_w'¶ The prefix to be used in C code for field size constants.


class
xentica.core.topology.lattice.
OrthogonalLattice
¶ Bases:
xentica.core.topology.lattice.Lattice
Ndimensional orthogonal lattice.
Points are all possible positive integer coordinates.

coord_to_index_code
(coord_prefix)¶ Implement cell’s index obtaining by coordinates in C.
See
Lattice.coord_to_index_code()
for details.

index_to_coord
(idx, bsca)¶ Implement coordinates obtaining by cell’s index in Python.
See
Lattice.index_to_coord()
for details.

index_to_coord_code
(index_name, coord_prefix)¶ Implement coordinates obtaining by cell’s index in C.
See
Lattice.index_to_coord_code()
for details.

is_off_board_code
(coord_prefix)¶ Implement off board cell obtaining in C.
See
Lattice.is_off_board_code()
for details.

supported_dimensions
= [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99]¶ Overridden value for supported dimensions.

Neighborhood (xentica.core.topology.neighborhood)¶
The collection of classes describing different neighborhood topologies.
All classes there are intended to be used inside Topology
for
neighborhood
class variable definition. They are also available via
xentica.core
shortcut. The example:
from xentica.core import CellularAutomaton, MooreNeighborhood
class MyCA(CellularAutomaton):
class Topology:
neighborhood = MooreNeighborhood()
# ...
# ...

class
xentica.core.topology.neighborhood.
Neighborhood
¶ Bases:
xentica.core.topology.mixins.DimensionsMixin
Base class for all neighborhood topologies.
For correct behavior, neighborhood classes should be inherited from this class. You should also implement the following functions:
See the detailed description below.

neighbor_coords
(index, coord_prefix, neighbor_prefix)¶ Generate C code to obtain neighbor coordinates by its index.
This is an abstract method, you must implement it in
Neighborhood
subclasses.Parameters:  index – Neighbor index, a nonnegative integer less than number of neighbors.
 coord_prefix – The prefix for variables containing main cell’s coordinates.
 neighbor_prefix – The prefix for resulting variables containing neighbor coordinates.
Returns: A string with C code doing all necessary to get neighbor state from RAM. No assignment, only a valid expression needed.

neighbor_state
(neighbor_index, state_index, coord_prefix)¶ Generate C code to obtain neighbor state by its index.
This is an abstract method, you must implement it in
Neighborhood
subclasses.Parameters:  neighbor_index – Neighbor index, a nonnegative integer less than number of neighbors.
 state_index – State index, a nonnegative integer less than number of neighbors for buffered states or 1 for main state.
 coord_prefix – The prefix for variables containing neighbor coordinates.
Returns: A string with C code doing all necessary to process neighbors’s coordinates and store them to neighbor coordinates variables.

num_neighbors
= None¶ Number of neighbors, you must redefine it in subclasses.

topology
= None¶ A reference to
Topology
holder class, will be set inBSCA
metaclass.


class
xentica.core.topology.neighborhood.
OrthogonalNeighborhood
¶ Bases:
xentica.core.topology.neighborhood.Neighborhood
Base class for neighborhoods on orthogonal lattice.
It is implementing all necessary
Neighborhood
abstract methods, the only thing you should override isdimensions()
setter. Indimensions()
, you should correctly setnum_neighbors
and_neighbor_deltas
attributes.
neighbor_coords
(index, coord_prefix, neighbor_prefix)¶ Implement neighbor coordinates obtaining by its index, in C.
See
Neighborhood.neighbor_coords()
for details.

neighbor_state
(neighbor_index, state_index, coord_prefix)¶ Implement state obtaining by neighbor/state index, in C.
See
Neighborhood.neighbor_coords()
for details.

supported_dimensions
= [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99]¶ Any number of dimentions is supported, 100 is just to limit your hyperspatial hunger.


class
xentica.core.topology.neighborhood.
MooreNeighborhood
¶ Bases:
xentica.core.topology.neighborhood.OrthogonalNeighborhood
Ndimensional Moore neighborhood implementation.
The neighbors are all cells, sharing at least one vertex.

dimensions
¶ Get a number of dimensions.


class
xentica.core.topology.neighborhood.
VonNeumannNeighborhood
¶ Bases:
xentica.core.topology.neighborhood.OrthogonalNeighborhood
Ndimensional Von Neumann neighborhood implementation.
The neighbors are adjacent cells in all possible orthogonal directions.

dimensions
¶ Get a number of dimensions.

Border (xentica.core.topology.border)¶
The collection of classes describing different types of field borders.
All classes there are intended to be used inside Topology
for
border
class variable definition. They are also available via
xentica.core
shortcut. The example:
from xentica.core import CellularAutomaton, TorusBorder
class MyCA(CellularAutomaton):
class Topology:
border = TorusBorder()
# ...
# ...

class
xentica.core.topology.border.
Border
¶ Bases:
xentica.core.topology.mixins.DimensionsMixin
Base class for all types of borders.
You should not inherit your borders directly from this class, use either
WrappedBorder
orGeneratedBorder
base subclasses for this.

class
xentica.core.topology.border.
WrappedBorder
¶ Bases:
xentica.core.topology.border.Border
Base class for borders wrapping the field into different manifolds.
For correct behavior, you should implement
wrap_coords()
method.See the detailed description below.

wrap_coords
(coord_prefix)¶ Generate C code to translate offboard coordinates to onboard ones.
This is an abstract method, you must implement it in
WrappedBorder
subclasses.Parameters: coord_prefix – The prefix for variables containing cell’s coordinates.


class
xentica.core.topology.border.
GeneratedBorder
¶ Bases:
xentica.core.topology.border.Border
Base class for borders generating states of the offboard cells.
For correct behavior, you should implement
off_board_state()
method.See the detailed description below.

off_board_state
(coord_prefix)¶ Generate C code to obtain offboard cell’s state.
This is an abstract method, you must implement it in
GeneratedBorder
subclasses.Parameters: coord_prefix – The prefix for variables containing cell’s coordinates.


class
xentica.core.topology.border.
TorusBorder
¶ Bases:
xentica.core.topology.border.WrappedBorder
Wraps the entire field into Ntorus manifold.
This is the most common type of border, allowing you to generate seamless tiles for wallpapers.

supported_dimensions
= [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99]¶ Any number of dimentions is supported, 100 is just to limit your hyperspatial hunger.

wrap_coords
(coord_prefix)¶ Impement coordinates wrapping to torus.
See
WrappedBorder.wrap_coords()
for details.


class
xentica.core.topology.border.
StaticBorder
(value=0)¶ Bases:
xentica.core.topology.border.GeneratedBorder
Generates a static value for every offboard cell.
This is acting like your field is surrounded by cells with the same predefined state.
The default is just an empty (zero) state.

off_board_state
(coord_prefix)¶ Impement offboard cells’ values obtaining.
See
GeneratedBorder.off_board_state()
for details.

supported_dimensions
= [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99]¶

Mixins (xentica.core.topology.mixins)¶
The collection of mixins to be used in core classes.
Would be interesting only if you are planning to hack into Xentica core functionality.

class
xentica.core.topology.mixins.
DimensionsMixin
¶ Bases:
object
The base functionality for classes, operating on a number of dimensions.
Adds
dimensions
property to a class, and checks it automatically over a list of allowed dimensions.
allowed_dimension
(num_dim)¶ Test if particular dimensionality is allowed.
Parameters: num_dim – Numbers of dimensions to test Returns: Boolean value, either dimensionality is allowed or not.

dimensions
¶ Get a number of dimensions.

supported_dimensions
= []¶ A list of integers, containing supported dimensionality. You must set it manually for every class using
DimensionsMixin
.
