def __init__(self, attr, count=1, limit=None, assure=False, **kwargs):
"""
Parameters
----------
attr : str or list(str)
Name of the to-be-permuted attribute. This can also be a list of
attribute names, in which case the *identical* shuffling is applied to
all listed attributes.
count : int
Number of permutations to yielded by .generate()
limit : None or str or dict
If ``None`` all attribute values will be permuted. If an single
attribute name is given, its unique values will be used to define
chunks of data that are permuted individually (i.e. no attributed
values will be replaced across chunks). Finally, if a dictionary is
provided, its keys define attribute names and its values (single value
or sequence thereof) attribute value, where all key-value combinations
across all given items define a "selection" of to-be-permuted samples
or features.
assure : bool
If set, by-chance non-permutations will be prevented, i.e. it is
checked that at least two items change their position. Since this
check adds a runtime penalty it is off by default.
"""
Node.__init__(self, **kwargs)
self._pattr = attr
self.nruns = count
self._limit = limit
self._pcfg = None
self._assure_permute = assure
def __init__(self,
count=None,
selection_strategy='equidistant',
attr='chunks',
space='partitions',
**kwargs):
"""
Parameters
----------
count : None or int
Desired number of splits to be output. It is limited by the
number of splits possible for a given splitter
(e.g. `OddEvenSplitter` can have only up to 2 splits). If None,
all splits are output (default).
selection_strategy : str
If `count` is not None, possible strategies are possible:
'first': First `count` splits are chosen;
'random': Random (without replacement) `count` splits are chosen;
'equidistant': Splits which are equidistant from each other.
attr : str
Sample attribute used to determine splits.
space : str
Name of the to be created sample attribute defining the partitions.
In addition, a dataset attribute named '`space`_set' will be added
to each output dataset, indicating the number of the partition set
it corresponds to.
"""
Node.__init__(self, space=space, **kwargs)
# pylint happyness block
self.__splitattr = attr
# we don't check it, thus no reason to make it private.
# someone might find it useful to change post creation
# TODO utilize such (or similar) policy through out the code
self.count = count
self._set_selection_strategy(selection_strategy)
def __init__(self, fx, space, **kwargs):
"""
Parameters
----------
fx : callable
Callable that is passed with the dataset samples as first and
attribute values as second argument.
space : str
name of the sample attribute that contains the target values.
"""
Node.__init__(self, space=space, **kwargs)
self.fx = fx
def __init__(self, count, space='repetitons', **kwargs):
"""
Parameters
----------
count : int
Positive integer that set the numbed of repetitions.
space : str
The name of the dataset attribute that will hold the actual repetiton
in the yielded datasets.
"""
Node.__init__(self, space=space, **kwargs)
self.nruns = count
def __init__(self, includes, *args, **kwargs):
"""
Parameters
----------
includes : list
List of tuples rules (attribute, unique_values) where all
listed 'unique_values' must be present in the dataset.
Matching samples or features get selected to proceed to the
next rule in the list. If at some point not all listed
values of the attribute are present, dataset does not pass
through the 'Sifter'.
"""
Node.__init__(self, *args, **kwargs)
self._includes = includes
def __init__(self,
amount='equal',
attr='targets',
count=1,
limit='chunks',
apply_selection=False,
space='balanced_set',
**kwargs):
"""
Parameters
----------
amount : {'equal'} or int or float
Specify the amount of elements to be selected (within the current
``limit``). The amount can be given as an integer value corresponding
to the absolute number of elements per unique attribute (see ``attr``)
value, as a float corresponding to the fraction of elements, or with
the keyword 'equal'. In the latter case the number of to be selected
elements is determined by the least number of available elements for
any given unique attribute value within the current limit.
attr : str
Dataset attribute whose unique values define element classes that are
to be balanced in number.
count : int
How many iterations to perform on ``generate()``.
limit : None or str or dict
If ``None`` the whole dataset is considered as one. If an single
attribute name is given, its unique values will be used to define
chunks of data that are balanced individually. Finally, if a
dictionary is provided, its keys define attribute names and its values
(single value or sequence thereof) attribute value, where all
key-value combinations across all given items define a "selection" of
to-be-balanced samples or features.
apply_selection : bool
Flag whether the balanced selection shall be applied, i.e. the output
dataset only contains selected elements. If False, the selection is
instead added as an attribute that merely marks selected elements (see
``space`` argument).
space : str
Name of the selection marker attribute in the output dataset that is
created if the balanced selection is not applied to the output dataset
(see ``apply_selection`` argument).
"""
Node.__init__(self, space=space, **kwargs)
self._amount = amount
self._attr = attr
self.nruns = count
self._limit = limit
self._limit_filter = None
self._apply_selection = apply_selection
def __init__(self, auto_train=False, force_train=False, **kwargs):
"""
Parameters
----------
auto_train : bool
Flag whether the learner will automatically train itself on the input
dataset when called untrained.
force_train : bool
Flag whether the learner will enforce training on the input dataset
upon every call.
**kwargs
All arguments are passed to the baseclass.
"""
Node.__init__(self, **kwargs)
self.__is_trained = False
self.__auto_train = auto_train
self.__force_train = force_train
def __init__(self, space, prestrip, poststrip, **kwargs):
"""
Parameters
----------
space : str
name of the sample attribute that shall be used to determine the
boundaries.
prestrip : int
Number of samples to be stripped prior to each boundary.
poststrip : int
Number of samples to be stripped after each boundary (this includes
the boundary sample itself, i.e. the first samples with a different
sample attribute value).
"""
Node.__init__(self, space=space, **kwargs)
self._prestrip = prestrip
self._poststrip = poststrip
def __init__(self, attr, attr_values=None, count=None, noslicing=False,
reverse=False, ignore_values=None, **kwargs):
"""
Parameters
----------
attr : str
Typically the sample or feature attribute used to determine splits.
attr_values : tuple
If not None, this is a list of value of the ``attr`` used to determine
the splits. The order of values in this list defines the order of the
resulting splits. It is possible to specify a particular value
multiple times. All dataset samples with values that are not listed
are going to be ignored.
count : None or int
Desired number of generated splits. If None, all splits are output
(default), otherwise the number of splits is limited to the given
``count`` or the maximum number of possible split (whatever is less).
noslicing : bool
If True, dataset splitting is not done by slicing (causing
shared data between source and split datasets) even if it would
be possible. By default slicing is performed whenever possible
to reduce the memory footprint.
reverse : bool
If True, the order of datasets in the split is reversed, e.g.
instead of (training, testing), (training, testing) will be spit
out.
ignore_values : tuple
If not None, this is a list of value of the ``attr`` the shall be
ignored when determining the splits. This settings also affects
any specified ``attr_values``.
"""
Node.__init__(self, space=attr, **kwargs)
self.__splitattr_values = attr_values
self.__splitattr_ignore = ignore_values
self.__count = count
self.__noslicing = noslicing
self.__reverse = reverse
