from sklearn.neighbors import KNeighborsClassifier
from immuneML.encodings.distance_encoding.CompAIRRDistanceEncoder import CompAIRRDistanceEncoder
from immuneML.encodings.distance_encoding.DistanceEncoder import DistanceEncoder
from immuneML.ml_methods.SklearnMethod import SklearnMethod
from scripts.specification_util import update_docs_per_mapping
[docs]class PrecomputedKNN(SklearnMethod):
"""
This is a wrapper of scikit-learn’s KNeighborsClassifier class.
This ML method takes a pre-computed distance matrix, as created by the :ref:`Distance` or :ref:`CompAIRRDistance` encoders.
If you would like to use a different encoding in combination with KNN, please use :ref:`KNN` instead.
Please see the `scikit-learn documentation <https://scikit-learn.org/stable/modules/generated/sklearn.neighbors.KNeighborsClassifier.html>`_
of KNeighborsClassifier for the parameters.
For usage instructions, check :py:obj:`~immuneML.ml_methods.SklearnMethod.SklearnMethod`.
YAML specification:
.. indent with spaces
.. code-block:: yaml
my_knn_method:
KNN:
# sklearn parameters (same names as in original sklearn class)
weights: uniform # always use this setting for weights
n_neighbors: [5, 10, 15] # find the optimal number of neighbors
# Additional parameter that determines whether to print convergence warnings
show_warnings: True
# if any of the parameters under KNN is a list and model_selection_cv is True,
# a grid search will be done over the given parameters, using the number of folds specified in model_selection_n_folds,
# and the optimal model will be selected
model_selection_cv: True
model_selection_n_folds: 5
# alternative way to define ML method with default values:
my_default_knn: KNN
"""
# todo raise error if the given encoded data is not a distance matrix?
def __init__(self, parameter_grid: dict = None, parameters: dict = None):
parameters = parameters if parameters is not None else {}
parameter_grid = parameter_grid if parameter_grid is not None else {}
super(PrecomputedKNN, self).__init__(parameter_grid=parameter_grid, parameters=parameters)
def _get_ml_model(self, cores_for_training: int = 2, X=None):
params = self._parameters
params["n_jobs"] = cores_for_training
params["metric"] = "precomputed"
return KNeighborsClassifier(**params)
[docs] def get_params(self):
return self.model.get_params(deep=True)
[docs] def can_predict_proba(self) -> bool:
return True
[docs] def get_compatible_encoders(self):
return [DistanceEncoder, CompAIRRDistanceEncoder]
[docs] @staticmethod
def get_documentation():
doc = str(PrecomputedKNN.__doc__)
mapping = {
"For usage instructions, check :py:obj:`~immuneML.ml_methods.SklearnMethod.SklearnMethod`.": SklearnMethod.get_usage_documentation("KNN"),
}
doc = update_docs_per_mapping(doc, mapping)
return doc