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#!/usr/bin/env python
import numpy as np
import pandas as pd
from sklearn.cluster import KMeans as _KMeans
from base import BaseAlgo, ClustererMixin
from codec import codecs_manager
from util.param_util import convert_params
from util import df_util
class KMeans(ClustererMixin, BaseAlgo):
def __init__(self, options):
self.handle_options(options)
out_params = convert_params(
options.get('params', {}), ints=['k', 'random_state'], aliases={'k': 'n_clusters'}
)
self.estimator = _KMeans(**out_params)
def summary(self, options):
if len(options) != 2: # only model name and mlspl_limits
raise RuntimeError(
'"%s" models do not take options for summarization' % self.__class__.__name__
)
df = pd.DataFrame(data=self.estimator.cluster_centers_, columns=self.columns)
df['cluster'] = pd.Series(
list(map(str, list(range(len(self.estimator.cluster_centers_))))), df.index
)
idf = pd.DataFrame(data=[self.estimator.inertia_], columns=['inertia'])
return pd.concat([df, idf], axis=0, ignore_index=True)
def apply(self, df, options):
"""Apply is overridden to add additional 'cluster_distance' column."""
# Make a copy of data, to not alter original dataframe
X = df.copy()
X, nans, _ = df_util.prepare_features(
X=X,
variables=self.feature_variables,
final_columns=self.columns,
mlspl_limits=options.get('mlspl_limits'),
)
y_hat = self.estimator.predict(X.values)
default_name = 'cluster'
output_name = options.get('output_name', default_name)
output = df_util.create_output_dataframe(
y_hat=y_hat, nans=nans, output_names=output_name
)
df_values = X[self.columns].values
cluster_ctrs = self.estimator.cluster_centers_
dist = [
np.nan if np.isnan(cluster) else np.sum(np.square(cluster_ctrs[cluster] - row))
for (cluster, row) in zip(y_hat, df_values)
]
dist_df = df_util.create_output_dataframe(
y_hat=dist, nans=nans, output_names='cluster_distance'
)
output = df_util.merge_predictions(output, dist_df)
df = df_util.merge_predictions(df, output)
df[output_name] = df[output_name].apply(lambda c: '' if np.isnan(c) else int(c))
return df
@staticmethod
def register_codecs():
from codec.codecs import SimpleObjectCodec
codecs_manager.add_codec('algos.KMeans', 'KMeans', SimpleObjectCodec)
codecs_manager.add_codec('sklearn.cluster._kmeans', 'KMeans', SimpleObjectCodec)