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#!usr/bin/env python |
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import itertools |
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import numpy as np |
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from sklearn.ensemble import RandomForestClassifier |
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from sklearn.ensemble import ExtraTreesClassifier |
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from sklearn.model_selection import train_test_split |
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from sklearn.metrics import accuracy_score |
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class gcForest(object): |
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max_acc = 0.0 |
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max_pred_layer = [] |
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def __init__(self, n_mgsRFtree=30, cascade_test_size=0.2, n_cascadeRF=2, |
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n_cascadeRFtree=101, cascade_layer=np.inf, |
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min_samples_cascade=0.05, tolerance=0.0): |
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setattr(self, 'n_layer', 0) |
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setattr(self, '_n_samples', 0) |
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setattr(self, 'n_cascadeRF', int(n_cascadeRF)) |
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setattr(self, 'cascade_test_size', cascade_test_size) |
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setattr(self, 'n_mgsRFtree', int(n_mgsRFtree)) |
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setattr(self, 'n_cascadeRFtree', int(n_cascadeRFtree)) |
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setattr(self, 'cascade_layer', cascade_layer) |
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setattr(self, 'min_samples_cascade', min_samples_cascade) |
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setattr(self, 'tolerance', tolerance) |
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def fit(self, X, y): |
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_ = self.cascade_forest(X, y) |
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def predict_proba(self, X): |
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cascade_all_pred_prob = self.cascade_forest(X) |
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predict_proba = np.mean(cascade_all_pred_prob, axis=0) |
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return predict_proba |
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def predict(self, X): |
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pred_proba = self.predict_proba(X=X) |
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predictions = np.argmax(pred_proba, axis=1) |
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return predictions |
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def cascade_forest(self, X, y=None): |
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if y is not None: |
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setattr(self, 'n_layer', 0) |
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test_size = getattr(self, 'cascade_test_size') |
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max_layers = getattr(self, 'cascade_layer') |
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tol = getattr(self, 'tolerance') |
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# test_size = int(np.floor(X.shape[0] * test_size)) |
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# train_size = X.shape[0] - test_size |
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# X_train = X[0:train_size, :] |
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# y_train = y[0:train_size] |
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# X_test = X[train_size:train_size + test_size, :] |
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# y_test = y[train_size:train_size + test_size] |
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# X_train, X_test, y_train, y_test = \ |
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# train_test_split(X, y, test_size=test_size) |
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X_train = X |
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X_test = X |
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y_train = y |
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y_test = y |
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self.n_layer += 1 |
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prf_pred_ref = self._cascade_layer(X_train, y_train) |
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accuracy_ref = self._cascade_evaluation(X_test, y_test) |
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feat_arr = self._create_feat_arr(X_train, prf_pred_ref) |
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self.n_layer += 1 |
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prf_pred_layer = self._cascade_layer(feat_arr, y_train) |
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accuracy_layer = self._cascade_evaluation(X_test, y_test) |
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max_acc = accuracy_ref |
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max_pred_layer = prf_pred_layer |
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while accuracy_layer > (accuracy_ref + tol) and self.n_layer <= max_layers: |
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#while accuracy_layer > (accuracy_ref - 0.000001) and \ |
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# self.n_layer <= max_layers: |
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if accuracy_layer > max_acc: |
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max_acc = accuracy_layer |
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max_pred_layer = prf_pred_layer |
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accuracy_ref = accuracy_layer |
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prf_pred_ref = prf_pred_layer |
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feat_arr = self._create_feat_arr(X_train, prf_pred_ref) |
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self.n_layer += 1 |
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prf_pred_layer = self._cascade_layer(feat_arr, y_train) |
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accuracy_layer = self._cascade_evaluation(X_test, y_test) |
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if accuracy_layer < accuracy_ref: |
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n_cascadeRF = getattr(self, 'n_cascadeRF') |
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for irf in range(n_cascadeRF): |
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delattr(self, '_casprf{}_{}'.format(self.n_layer, irf)) |
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delattr(self, '_cascrf{}_{}'.format(self.n_layer, irf)) |
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self.n_layer -= 1 |
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print("layer %d - accuracy %f ref %f" % (self.n_layer, accuracy_layer, accuracy_ref)) |
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else: |
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at_layer = 1 |
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prf_pred_ref = self._cascade_layer(X, layer=at_layer) |
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while at_layer < getattr(self, 'n_layer'): |
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at_layer += 1 |
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feat_arr = self._create_feat_arr(X, prf_pred_ref) |
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prf_pred_ref = self._cascade_layer(feat_arr, layer=at_layer) |
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return prf_pred_ref |
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def _cascade_layer(self, X, y=None, layer=0): |
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n_tree = getattr(self, 'n_cascadeRFtree') |
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n_cascadeRF = getattr(self, 'n_cascadeRF') |
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min_samples = getattr(self, 'min_samples_cascade') |
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prf = RandomForestClassifier( |
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n_estimators=100, max_features=8, |
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bootstrap=True, criterion="entropy", min_samples_split=20, |
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max_depth=None, class_weight='balanced', oob_score=True) |
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crf = ExtraTreesClassifier( |
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n_estimators=100, max_depth=None, |
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bootstrap=True, oob_score=True) |
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prf_pred = [] |
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if y is not None: |
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# print('Adding/Training Layer, n_layer={}'.format(self.n_layer)) |
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for irf in range(n_cascadeRF): |
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prf.fit(X, y) |
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crf.fit(X, y) |
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setattr(self, '_casprf{}_{}'.format(self.n_layer, irf), prf) |
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setattr(self, '_cascrf{}_{}'.format(self.n_layer, irf), crf) |
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probas = prf.oob_decision_function_ |
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probas += crf.oob_decision_function_ |
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prf_pred.append(probas) |
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elif y is None: |
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for irf in range(n_cascadeRF): |
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prf = getattr(self, '_casprf{}_{}'.format(layer, irf)) |
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crf = getattr(self, '_cascrf{}_{}'.format(layer, irf)) |
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probas = prf.predict_proba(X) |
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probas += crf.predict_proba(X) |
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prf_pred.append(probas) |
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return prf_pred |
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def _cascade_evaluation(self, X_test, y_test): |
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casc_pred_prob = np.mean(self.cascade_forest(X_test), axis=0) |
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casc_pred = np.argmax(casc_pred_prob, axis=1) |
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casc_accuracy = accuracy_score(y_true=y_test, y_pred=casc_pred) |
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#print('Layer validation accuracy = {}'.format(casc_accuracy)) |
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return casc_accuracy |
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def _create_feat_arr(self, X, prf_pred): |
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swap_pred = np.swapaxes(prf_pred, 0, 1) |
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add_feat = swap_pred.reshape([np.shape(X)[0], -1]) |
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feat_arr = np.concatenate([add_feat, X], axis=1) |
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return feat_arr |
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