Package mvpa :: Package datasets :: Module splitters :: Class NFoldSplitter

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# Class NFoldSplitter

source code

Generic N-fold data splitter.

Provide folding splitting. Given a dataset with N chunks, with cvtype=1 (which is default), it would generate N splits, where each chunk sequentially is taken out (with replacement) for cross-validation. Example, if there is 4 chunks, splits for cvtype=1 are:

> [[1, 2, 3], [0]] [[0, 2, 3], [1]] [[0, 1, 3], [2]] [[0, 1, 2], [3]]

If cvtype>1, then all possible combinations of cvtype number of chunks are taken out for testing, so for cvtype=2 in previous example:

> [[2, 3], [0, 1]] [[1, 3], [0, 2]] [[1, 2], [0, 3]] [[0, 3], [1, 2]] [[0, 2], [1, 3]] [[0, 1], [2, 3]]

Instance Methods | [hide private]

__init__(self, cvtype=1, **kwargs) Initialize the N-fold splitter. | source code

__str__(self) String summary over the object | source code

_getSplitConfig(self, uniqueattrs) Returns proper split configuration for N-M fold split. | source code

Inherited from `Splitter`: `__call__`, `setNPerLabel`, `splitDataset`, `splitcfg` Inherited from `Splitter` (private): `_setStrategy` Inherited from `object`: `__delattr__`, `__format__`, `__getattribute__`, `__hash__`, `__new__`, `__reduce__`, `__reduce_ex__`, `__repr__`, `__setattr__`, `__sizeof__`, `__subclasshook__`

Class Variables | [hide private]

| __doc__ = `enhancedDocString('NFoldSplitter', locals(), Splitter)`
Inherited from `Splitter`: `strategy` Inherited from `Splitter` (private): `_NPERLABEL_STR`, `_STRATEGIES`

Instance Variables | [hide private]

Inherited from `Splitter`: `count`

Properties | [hide private]

Inherited from `object`: `__class__`

Method Details | [hide private]

### __init__(self, cvtype=1, **kwargs)
(Constructor)

source code

Initialize the N-fold splitter.

Parameters:
  - `cvtype`, `int` - Type of cross-validation: N-(cvtype)
  - `kwargs` - Additional parameters are passed to the Splitter base class.
Overrides: object.__init__

### __str__(self)
(Informal representation operator)

source code

String summary over the object

Overrides: object.__str__

### _getSplitConfig(self, uniqueattrs)

source code

Returns proper split configuration for N-M fold split.

Overrides: Splitter._getSplitConfig