Class Cover
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object +

Cover
 Known Subclasses:

Class representing a cover of an arbitrary ordered set.
Covers are similar to clusterings, but each element of the set may
belong to more than one cluster in a cover, and elements not belonging to
any cluster are also allowed.
Cover
instances provide a similar API as Clustering instances; for instance, iterating over a Cover will
iterate over the clusters just like with a regular Clustering instance. However, they are not derived from
each other or from a common superclass, and there might be functions that
exist only in one of them or the other.
Clusters of an individual cover can be accessed by the []
operator:
>>> cl = Cover([[0,1,2,3], [2,3,4], [0,1,6]])
>>> cl[0]
[0, 1, 2, 3]
The membership vector can be accessed by the membership
property. Note that contrary to Clustering instances, the membership vector will contain
lists that contain the cluster indices each item belongs to:
>>> cl.membership
[[0, 2], [0, 2], [0, 1], [0, 1], [1], [], [2]]
The number of clusters can be retrieved by the len
function:
>>> len(cl)
3
You can iterate over the cover as if it were a regular list of
clusters:
>>> for cluster in cl:
... print " ".join(str(idx) for idx in cluster)
...
0 1 2 3
2 3 4
0 1 6
If you need all the clusters at once as lists, you can simply convert
the cover to a list:
>>> cluster_list = list(cl)
>>> print cluster_list
[[0, 1, 2, 3], [2, 3, 4], [0, 1, 6]]
Clustering objects can readily be converted to Cover objects
using the constructor:
>>> clustering = Clustering([0, 0, 0, 0, 1, 1, 1, 2, 2, 2])
>>> cover = Cover(clustering)
>>> list(clustering) == list(cover)
True



__getitem__(self,
index)
Returns the cluster with the given index. 
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__iter__(self)
Iterates over the clusters in this cover. 
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__len__(self)
Returns the number of clusters in this cover. 
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Inherited from object :
__delattr__ ,
__format__ ,
__getattribute__ ,
__hash__ ,
__new__ ,
__reduce__ ,
__reduce_ex__ ,
__repr__ ,
__setattr__ ,
__sizeof__ ,
__subclasshook__


membership
Returns the membership vector of this cover.


n
Returns the number of elements in the set covered by this cover.

Inherited from object :
__class__

__init__(self,
clusters,
n=0)
(Constructor)
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Constructs a cover with the given clusters.
 Parameters:
clusters  the clusters in this cover, as a list or iterable. Each cluster
is specified by a list or tuple that contains the IDs of the
items in this cluster. IDs start from zero.
n  the total number of elements in the set that is covered by this
cover. If it is less than the number of unique elements found in
all the clusters, we will simply use the number of unique
elements, so it is safe to leave this at zero. You only have to
specify this parameter if there are some elements that are
covered by none of the clusters.
 Overrides:
object.__init__

__str__(self)
(Informal representation operator)
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Returns a string representation of the cover.
 Overrides:
object.__str__

Returns the size of a given cluster.
 Parameters:
idx  the cluster in which we are interested.

Returns the size of given clusters.
The indices are given as positional arguments. If there are no
positional arguments, the function will return the sizes of all
clusters.

Returns the histogram of cluster sizes.
 Parameters:
bin_width  the bin width of the histogram
 Returns:
 a Histogram object

Returns the summary of the cover.
The summary includes the number of items and clusters, and also the
list of members for each of the clusters if the verbosity is nonzero.
 Parameters:
verbosity  determines whether the cluster members should be printed. Zero
verbosity prints the number of items and clusters only.
 Returns:
 the summary of the cover as a string.

membership
Returns the membership vector of this cover.
The membership vector of a cover covering n elements is a list
of length n, where element i contains the cluster indices
of the ith item.
 Get Method:
 unreachable.membership(self)
 Returns the membership vector of this cover.

n
Returns the number of elements in the set covered by this cover.
 Get Method:
 unreachable.n(self)
 Returns the number of elements in the set covered by this cover.
