Variables

Abstract variables

Variables functionnalities can be extended with Addons.

class Variable(label, **kwargs)[source]

Bases: abc.ABC

Variables is an Abstract class defining what a variable is in a Search space.

Parameters

  • label (str) – Name of the variable.

  • kwargs (dict) – Kwargs will be the different addons you want to add to a Variables. Known addons are: * to_discrete : VarConverter * to_continuous : VarConverter * neighbor : VarNeighborhood

label
abstract random(size=None)[source]
abstract isconstant()[source]
abstract subset()[source]

Base variables

Basic Variables are the low level bricks to define a variable in Zellij.

class IntVar(label, lower, upper, sampler=<built-in method randint of numpy.random.mtrand.RandomState object>, **kwargs)[source]

Bases: zellij.core.variables.Variable

IntVar is a Variables discribing an Integer variable. T he lower and upper bounds are included.

Parameters

  • label (str) – Name of the variable.

  • lower (int) – Lower bound of the variable

  • upper (int) – Upper bound of the variable

  • sampler (Callable, default=np.random.randint) – Function that takes lower bound, upper bound and a size as parameters.

up_bound

Lower bound of the variable

Type

int

low_bound

Upper bound of the variable

Type

int

Examples

>>> from zellij.core.variables import IntVar
>>> a = IntVar("test", 0, 5)
>>> print(a)
IntVar(test, [0;5])
>>> a.random()
1
random(size=None)[source]
Parameters

size (int, default=None) – Number of draws.

Returns

out – Return an int if size`=1, a :code:`list[int] else.

Return type

int or list[int]

isconstant()[source]
Returns

out – Return True, if this Variables is a constant (lower`==:code:`upper), False otherwise.

Return type

boolean

subset(lower, upper)[source]
class FloatVar(label, lower, upper, sampler=<built-in method uniform of numpy.random.mtrand.RandomState object>, tolerance=1e-14, **kwargs)[source]

Bases: zellij.core.variables.Variable

FloatVar is a Variables discribing a Float variable.

Parameters

  • label (str) – Name of the variable.

  • lower ({int,float}) – Lower bound of the variable

  • upper ({int,float}) – Upper bound of the variable

  • sampler (Callable, default=np.random.uniform) – Function that takes lower bound, upper bound and a size as parameters.

up_bound

Lower bound of the variable

Type

{int,float}

low_bound

Upper bound of the variable

Type

{int,float}

Examples

>>> from zellij.core.variables import FloatVar
>>> a = FloatVar("test", 0, 5.0)
>>> print(a)
FloatVar(test, [0;5.0])
>>> a.random()
2.2011985711663056
random(size=None)[source]
Parameters

size (int, default=None) – Number of draws.

Returns

out – Return a float if size`=1, a :code:`list[float] else.

Return type

float or list[float]

isconstant()[source]
Returns

out – Return True, if this Variables is a constant (lower`==:code:`upper), False otherwise.

Return type

boolean

subset(lower, upper)[source]
class CatVar(Variable)[source]

Bases: zellij.core.variables.Variable

CatVar is a Variables discribing what a categorical variable is.

Parameters

  • label (str) – Name of the variable.

  • features (list) – List of all choices.

  • weights (list[float]) – Weights associated to each elements of features. The sum of all positive elements of this list, must be equal to 1.

features
weights

Examples

>>> from zellij.core.variables import CatVar, IntVar
>>> a = CatVar("test", ['a', 1, 2.56, IntVar("int", 100 , 200)])
>>> print(a)
CatVar(test, ['a', 1, 2.56, IntVar(int, [100;200])])
>>> a.random(10)
['a', 180, 2.56, 'a', 'a', 2.56, 185, 2.56, 105, 1]
random(size=1)[source]
Parameters

size (int, default=1) – Number of draws.

Returns

out – Return a feature if size`=1, a :code:`list[features] else. Features can be Variables. When seleted, it will return a random point from this Variables.

Return type

float or list[float]

isconstant()[source]
Returns

out – Return True, if this Variables is a constant (len(feature)==1), False otherwise.

Return type

boolean

subset(lower, upper)[source]

Constant

The constant Variables should not be used. In particular conditions, it can sometimes replace a regular Variables, particularly for decomposition Metaheuristic. User should implement directly the constant inside the loss function.

class Constant(label, value, **kwargs)[source]

Bases: zellij.core.variables.Variable

Constant is a Variables discribing a constant of any type.

Parameters

  • label (str) – Name of the variable.

  • value (object) – Constant value

label

Name of the variable.

Type

str

value

Constant value

Type

object

Examples

>>> from zellij.core.variables import Constant
>>> a = Constant("test", 5)
>>> print(a)
Constant(test, 5)
>>> a.random()
5
random(size=None)[source]
Parameters

size (int, default=None) – Number of draws.

Returns

out – Return an int if size`=1, a :code:`list[self.value] else.

Return type

int or list[int]

isconstant()[source]
Returns

out – Return True

Return type

boolean

subset(l, u)[source]

Composed variables

Composed Variables are Variables made of other Variables.

class ArrayVar(Variable)[source]

Bases: zellij.core.variables.Variable

ArrayVar is a Variables describing a list of Variables. This class is iterable.

Parameters

  • label (str) – Name of the variable.

  • *args (list[Variable]) – Elements of the ArrayVar. All elements must be of type Variables

Examples

>>> from zellij.core.variables import ArrayVar, IntVar, FloatVar, CatVar
>>> a = ArrayVar(IntVar("int_1", 0,8),
...              IntVar("int_2", 4,45),
...              FloatVar("float_1", 2,12),
...              CatVar("cat_1", ["Hello", 87, 2.56]))
>>> print(a)
ArrayVar(, [IntVar(int_1, [0;8]),
            IntVar(int_2, [4;45]),
            FloatVar(float_1, [2;12]),
            CatVar(cat_1, ['Hello', 87, 2.56])])
>>> a.random()
[5, 15, 8.483221226216427, 'Hello']
random(size=1)[source]
Parameters

size (int, default=None) – Number of draws.

Returns

out – Return a list composed of the values returned by each Variables of ArrayVar. If size>1, return a list of list

Return type

float or list[float]

isconstant()[source]
Returns

out – Return True, if this Variables is a constant (all elements are constants), False otherwise.

Return type

boolean

subset(lower, upper)[source]
index(value)[source]

Return the index inside the :code:ArrayVar of a given value.

Parameters

value (Variable) – Targeted Variable in the ArrayVar

Returns

Index of value.

Return type

int

append(v)[source]

Append a Variables to the :code:ArrayVar.

Parameters

v (Variable) – Variable to be added to the ArrayVar

Future variables

Future Variables, are variables that are implemented in Zellij. However they are not yet supported by the whole package. (They cannot be save for example)

class Block(Variable)[source]

Bases: zellij.core.variables.Variable

A Block is a Variables which will repeat multiple times a Variables.

Parameters

  • label (str) – Name of the variable.

  • value (Variable) – Variables that will be repeated

  • repeat (int) – Number of repeats.

Examples

>>> from zellij.core.variables import Block, ArrayVar, FloatVar, IntVar
>>> content = ArrayVar("test",
...                     IntVar("int_1", 0,8),
...                     IntVar("int_2", 4,45),
...                     FloatVar("float_1", 2,12))
>>> a = Block("size 3 Block", content, 3)
>>> print(a)
Block(size 3 Block, [IntVar(int_1, [0;8]),
                     IntVar(int_2, [4;45]),
                     FloatVar(float_1, [2;12]),])
>>> a.random(3)
[[[7, 22, 6.843164591359903],
    [5, 18, 10.608957810018786],
    [4, 21, 10.999649079045858]],
[[5, 9, 9.773288692746476],
    [1, 12, 6.1909724243671445],
    [4, 12, 9.404313234593669]],
[[4, 10, 2.72648188721585],
    [1, 44, 5.319257221471118],
    [4, 24, 9.153357213126071]]]
random(size=1)[source]
Parameters

size (int, default=None) – Number of draws.

Returns

out – Return a list composed of the results from the Variables random() method, repeated repeat times. If size > 1, return a list of list.

Return type

float or list[float]

isconstant()[source]
Returns

out – Return True, if this Variables is a constant (the repeated Variables is constant), False otherwise.

Return type

boolean

subset(lower, upper)[source]
class DynamicBlock(Block)[source]

Bases: zellij.core.variables.Block

A DynamicBlock is a Block with a random number of repeats.

Parameters

  • label (str) – Name of the variable.

  • value (Variable) – Variables that will be repeated

  • repeat (int) – Maximum number of repeats.

Examples

>>> from zellij.core.variables import DynamicBlock, ArrayVar, FloatVar, IntVar
>>> content = ArrayVar(IntVar("int_1", 0,8),
...                    IntVar("int_2", 4,45),
...                    FloatVar("float_1", 2,12))
>>> a = DynamicBlock("max size 10 Block", content, 10)
>>> print(a)
DynamicBlock(max size 10 Block, [IntVar(int_1, [0;8]),
                                 IntVar(int_2, [4;45]),
                                 FloatVar(float_1, [2;12]),])
>>> a.random()
[[[3, 12, 10.662362255103403],
      [7, 9, 5.496860842510198],
      [3, 37, 7.25449459082227],
      [4, 28, 4.912883181322568]],
[[3, 23, 5.150228671772998]],
[[6, 30, 6.1181372194738515]]]
random(size=1)[source]
Parameters

size (int, default=None) – Number of draws.

Returns

out – Return a list composed of the results from the Variables random() method, repeated repeat times. If size > 1, return a list of list.

Return type

float or list[float]

isconstant()[source]
Returns

out – Return False, a dynamic block cannot be constant. (It is a binary)

Return type

False