# Copyright (c) 2017, System Engineering Software Society
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"""
Some of the docstrings for this module have been automatically
extracted from the `scikit-learn <http://scikit-learn.org/>`_ library
and are covered by their respective licenses.
"""
from __future__ import (print_function, division, unicode_literals,
                        absolute_import)
import sklearn, sklearn.tree
from sympathy.api import node
from sympathy.api.nodeconfig import Ports, Tag, Tags
from sylib.machinelearning.model import ModelPort
from sylib.machinelearning.decisiontrees import DecisionTreeDescriptor
from sylib.machinelearning.abstract_nodes import SyML_abstract
from sylib.machinelearning.utility import names_from_x
from sylib.machinelearning.descriptors import BoolType
from sylib.machinelearning.descriptors import FloatType
from sylib.machinelearning.descriptors import IntType
from sylib.machinelearning.descriptors import NoneType
from sylib.machinelearning.descriptors import StringSelectionType
from sylib.machinelearning.descriptors import UnionType
[docs]class DecisionTreeClassifier(SyML_abstract, node.Node):
    name = 'Decision Tree Classifier'
    author = 'Mathias Broxvall'
    copyright = '(C) 2017 System Engineering Software Society'
    version = '0.1'
    icon = 'tree.svg'
    description = (
        'Decision Trees (DTs) are a non-parametric supervised learning method'
        'used for classification and regression. The goal is to create a model'
        'that predicts the value of a target variable by learning simple'
        'decision rules inferred from the data features.'
    )
    nodeid = 'org.sysess.sympathy.machinelearning.decision_tree_classifier'
    tags = Tags(Tag.MachineLearning.Supervised)
    descriptor = DecisionTreeDescriptor()
    descriptor.name = name
    descriptor.set_info([
        {'name': 'max_depth',
         'type': UnionType(
             [IntType(min_value=1), NoneType()], default=3)},
        {'name': 'criterion',
         'type': StringSelectionType(['gini', 'entropy']),},
        {'name': 'splitter',
         'type': StringSelectionType(['best', 'random']),},
        {'name': 'max_features',
         'type': UnionType([
             IntType(min_value=1),
             FloatType(min_value=0, max_value=1),
             NoneType(),
             StringSelectionType(['auto', 'sqrt', 'log2'])
             ], default=None),},
        {'name': 'min_samples_split',
         'type': UnionType([IntType(min_value=0),
                            FloatType(min_value=0, max_value=1)], default=2),},
        {'name': 'min_samples_leaf',
         'type': UnionType([IntType(min_value=0),
                            FloatType(min_value=0, max_value=1)], default=1),},
        {'name': 'max_leaf_nodes',
         'type': UnionType([IntType(min_value=0), NoneType()], default=None),},
        {'name': 'min_impurity_split',
         'type': FloatType(default=1e-7),
         'deprecated': True,
        },
        {'name': 'min_impurity_decrease',
         'type': FloatType(default=0),},
        {'name': 'presort',
         'type': BoolType(default=False),},
         {'name': 'random_state',
          'type': UnionType([NoneType(), IntType()], default=None)},
    ], doc_class=sklearn.tree.DecisionTreeClassifier)
    descriptor.set_attributes([
        {'name': 'classes_'},
        {'name': 'feature_importances_', 'cnames': names_from_x},
        {'name': 'max_features_'},
        {'name': 'n_classes_'},
        {'name': 'n_features_'},
        {'name': 'n_outputs_'},
    ], doc_class = sklearn.tree.DecisionTreeClassifier)
    parameters = node.parameters()
    SyML_abstract.generate_parameters(parameters, descriptor)
    inputs = Ports([])
    outputs = Ports([ModelPort('Model','model')])
    __doc__ = SyML_abstract.generate_docstring(
        description, descriptor.info, descriptor.attributes, inputs, outputs)
    def execute(self, node_context):
        model = node_context.output['model']
        desc = self.__class__.descriptor
        model.set_desc(desc)
        kwargs = self.__class__.descriptor.get_parameters(
            node_context.parameters)
        skl = sklearn.tree.DecisionTreeClassifier(**kwargs)
        model.set_skl(skl)
        model.save()