--- a +++ b/Stats/_NaiveBayes.py @@ -0,0 +1,90 @@ +#!/usr/bin/env python +# -*- coding: UTF-8 -*- +# +# Copyright 2017 University of Westminster. All Rights Reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# ============================================================================== +""" It is an interface for the 'MultinomialNB' training model (Multinomial Naive Bayes). +""" + +from typing import Dict, List, Any, TypeVar +from Stats.Stats import Stats +from sklearn import naive_bayes + +PandasDataFrame = TypeVar('DataFrame') +SklearnMultinomialNB = TypeVar('MultinomialNB') + +__author__ = "Mohsen Mesgarpour" +__copyright__ = "Copyright 2016, https://github.com/mesgarpour" +__credits__ = ["Mohsen Mesgarpour"] +__license__ = "GPL" +__version__ = "1.1" +__maintainer__ = "Mohsen Mesgarpour" +__email__ = "mohsen.mesgarpour@gmail.com" +__status__ = "Release" + + +class _NaiveBayes(Stats): + def __init__(self): + """Initialise the objects and constants. + """ + super(self.__class__, self).__init__() + self._logger.debug("Run Naive Bayes.") + + def train(self, + features_indep_df: PandasDataFrame, + feature_target: List, + model_labals: List=[0, 1], + **kwargs: Any) -> SklearnMultinomialNB: + """Perform the training, using the Multinomial Naive Bayes. + :param features_indep_df: the independent features, which are inputted into the model. + :param feature_target: the target feature, which is being estimated. + :param model_labals: the target labels (default [0, 1]). + :param kwargs: alpha=1.0, fit_prior=True, class_prior=None + :return: the trained model. + """ + self._logger.debug("Train " + __name__) + model_train = naive_bayes.MultinomialNB(**kwargs) + model_train.fit(features_indep_df.values, feature_target) + return model_train + + def train_summaries(self, + model_train: SklearnMultinomialNB) -> Dict: + """Produce the training summary. + :param model_train: the instance of the trained model. + :return: the training summary. + """ + self._logger.debug("Summarise " + __name__) + summaries = dict() + summaries['class_log_prior_'] = model_train.class_log_prior_ + summaries['intercept_'] = model_train.intercept_ + summaries['feature_log_prob_'] = model_train.feature_log_prob_ + summaries['coef_'] = model_train.coef_ + summaries['class_count_'] = model_train.class_count_ + summaries['feature_count_'] = model_train.feature_count_ + return summaries + + def plot(self, + model_train: SklearnMultinomialNB, + feature_names: List, + class_names: List=["True", "False"]): + """Plot the tree diagram. + :param model_train: the instance of the trained model. + :param feature_names: the names of input features. + :param class_names: the predicted class labels. + :return: the model graph. + """ + self._logger.debug("Plot " + __name__) + # todo: plot + pass