Combinations

class Combinations(*args)

Combinations generator.

Available constructors:

Combinations()

Combinations(k, n)

Parameters
kinteger

The cardinal of the subsets

ninteger

The cardinal of the base set

See also

CombinatorialGenerator, KPermutations, Tuples

Notes

In the first usage, the generator is built using the default values k = 1, n = 1.

In the second usage, the generator produces all the subsets with k elements of a base set with n elements. The subsets are produced as a collection of Indices in lexical order, the elements of each subset being sorted in increasing order.

The number of indices generated is:

\frac{n!}{k! (n - k)!}

The combinations generator generates a collection of Indices where:

  • the Indices are sorted in lexical order,

  • the components are sorted within a given Indices.

Examples

>>> import openturns as ot
>>> tuples = ot.Combinations(2, 5)
>>> print(tuples.generate())
[[0,1],[0,2],[0,3],[0,4],[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]]#10

Methods

generate()

Generate the combinatorial sequence.

getClassName()

Accessor to the object's name.

getId()

Accessor to the object's id.

getK()

Accessor to the cardinal of the subsets.

getN()

Accessor to the cardinal of the base set.

getName()

Accessor to the object's name.

getShadowedId()

Accessor to the object's shadowed id.

getVisibility()

Accessor to the object's visibility state.

hasName()

Test if the object is named.

hasVisibleName()

Test if the object has a distinguishable name.

setK(k)

Accessor to the cardinal of the subsets.

setN(n)

Accessor to the cardinal of the base set.

setName(name)

Accessor to the object's name.

setShadowedId(id)

Accessor to the object's shadowed id.

setVisibility(visible)

Accessor to the object's visibility state.
__init__(*args)
generate()

Generate the combinatorial sequence.

Returns
indicesColcollection of Indices

The collection of all the possible values of the combinatorial generator as a set of non-negative integer values stored into an Indices.

getClassName()

Accessor to the object’s name.

Returns
class_namestr

The object class name (object.__class__.__name__).

getId()

Accessor to the object’s id.

Returns
idint

Internal unique identifier.

getK()

Accessor to the cardinal of the subsets.

Returns
kinteger

The cardinal of the subsets.

getN()

Accessor to the cardinal of the base set.

Returns
ninteger

The cardinal of the base set.

getName()

Accessor to the object’s name.

Returns
namestr

The name of the object.

getShadowedId()

Accessor to the object’s shadowed id.

Returns
idint

Internal unique identifier.

getVisibility()

Accessor to the object’s visibility state.

Returns
visiblebool

Visibility flag.

hasName()

Test if the object is named.

Returns
hasNamebool

True if the name is not empty.

hasVisibleName()

Test if the object has a distinguishable name.

Returns
hasVisibleNamebool

True if the name is not empty and not the default one.

setK(k)

Accessor to the cardinal of the subsets.

Parameters
kinteger

The cardinal of the subsets.

setN(n)

Accessor to the cardinal of the base set.

Parameters
ninteger

The cardinal of the base set.

setName(name)

Accessor to the object’s name.

Parameters
namestr

The name of the object.

setShadowedId(id)

Accessor to the object’s shadowed id.

Parameters
idint

Internal unique identifier.

setVisibility(visible)

Accessor to the object’s visibility state.

Parameters
visiblebool

Visibility flag.