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Estimator node gradual

This file is part of the TPOT library.

The current version of TPOT was developed at Cedars-Sinai by: - Pedro Henrique Ribeiro (https://github.com/perib, https://www.linkedin.com/in/pedro-ribeiro/) - Anil Saini (anil.saini@cshs.org) - Jose Hernandez (jgh9094@gmail.com) - Jay Moran (jay.moran@cshs.org) - Nicholas Matsumoto (nicholas.matsumoto@cshs.org) - Hyunjun Choi (hyunjun.choi@cshs.org) - Miguel E. Hernandez (miguel.e.hernandez@cshs.org) - Jason Moore (moorejh28@gmail.com)

The original version of TPOT was primarily developed at the University of Pennsylvania by: - Randal S. Olson (rso@randalolson.com) - Weixuan Fu (weixuanf@upenn.edu) - Daniel Angell (dpa34@drexel.edu) - Jason Moore (moorejh28@gmail.com) - and many more generous open-source contributors

TPOT is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

TPOT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with TPOT. If not, see http://www.gnu.org/licenses/.

EstimatorNodeIndividual_gradual

Bases: SklearnIndividual

Note that ConfigurationSpace does not support None as a parameter. Instead, use the special string "". TPOT will automatically replace instances of this string with the Python None.

Parameters:

Name Type Description Default
method type

The class of the estimator to be used

 required
space ConfigurationSpace | dict

The hyperparameter space to be used. If a dict is passed, hyperparameters are fixed and not learned.

 required
Source code in tpot2/search_spaces/nodes/estimator_node_gradual.py 
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class EstimatorNodeIndividual_gradual(SklearnIndividual):
    """
    Note that ConfigurationSpace does not support None as a parameter. Instead, use the special string "<NONE>". TPOT will automatically replace instances of this string with the Python None. 

    Parameters
    ----------
    method : type
        The class of the estimator to be used

    space : ConfigurationSpace|dict
        The hyperparameter space to be used. If a dict is passed, hyperparameters are fixed and not learned.

    """
    def __init__(self, method: type, 
                        space: ConfigurationSpace|dict, #TODO If a dict is passed, hyperparameters are fixed and not learned. Is this confusing? Should we make a second node type?
                        hyperparameter_parser: callable = None,
                        rng=None) -> None:
        super().__init__()
        self.method = method
        self.space = space

        if hyperparameter_parser is None:
            self.hyperparameter_parser = default_hyperparameter_parser
        else:
            self.hyperparameter_parser = hyperparameter_parser

        if isinstance(space, dict):
            self.hyperparameters = space
        else:
            rng = np.random.default_rng(rng)
            self.space.seed(rng.integers(0, 2**32))
            self.hyperparameters = dict(self.space.sample_configuration())

    def mutate(self, rng=None):
        if isinstance(self.space, dict): 
            return False
        self.hyperparameters = gradual_hyperparameter_update(params=self.hyperparameters, configspace=self.space, rng=rng)
        return True

    def crossover(self, other, rng=None):
        if isinstance(self.space, dict):
            return False

        rng = np.random.default_rng(rng)
        if self.method != other.method:
            return False

        #loop through hyperparameters, randomly swap items in self.hyperparameters with items in other.hyperparameters
        for hyperparameter in self.space:
            if rng.choice([True, False]):
                if hyperparameter in other.hyperparameters:
                    self.hyperparameters[hyperparameter] = other.hyperparameters[hyperparameter]

        return True


    @final #this method should not be overridden, instead override hyperparameter_parser
    def export_pipeline(self, **kwargs):
        return self.method(**self.hyperparameter_parser(self.hyperparameters))

    def unique_id(self):
        #return a dictionary of the method and the hyperparameters
        method_str = self.method.__name__
        params = list(self.hyperparameters.keys())
        params = sorted(params)

        id_str = f"{method_str}({', '.join([f'{param}={self.hyperparameters[param]}' for param in params])})"

        return id_str