Entropi vs Gini indeksi

Bu egzersizde dt_entropy'nin test kümesi doğruluğunu, dt_gini adlı başka bir ağacın doğruluğu ile karşılaştıracaksın. dt_gini ağacı, aynı veri kümesinde ve aynı parametrelerle eğitildi; tek fark, bilgi ölçütünün anahtar kelime 'gini' kullanılarak gini indeksine ayarlanmış olması.

X_test, y_test, dt_entropy ile birlikte, dt_gini tarafından test kümesinde elde edilen doğruluğa karşılık gelen accuracy_gini çalışma alanında mevcut.

Bu egzersiz

Python ile Ağaç Tabanlı Modellerle Machine Learning

kursunun bir parçasıdır

Kursu Görüntüle

Egzersiz talimatları

sklearn.metrics içinden accuracy_score'u içe aktar.
dt_entropy'nin test kümesi etiketlerini tahmin et ve sonucu y_pred değişkenine ata.
dt_entropy'nin test kümesi doğruluğunu değerlendir ve sonucu accuracy_entropy değişkenine ata.
accuracy_entropy ve accuracy_gini değerlerini incele.

Uygulamalı interaktif egzersiz

Bu örnek kodu tamamlayarak bu egzersizi bitirin.

# Import accuracy_score from sklearn.metrics
from ____.____ import ____

# Use dt_entropy to predict test set labels
____= ____.____(____)

# Evaluate accuracy_entropy
accuracy_entropy = ____(____, ____)

# Print accuracy_entropy
print(f'Accuracy achieved by using entropy: {accuracy_entropy:.3f}')

# Print accuracy_gini
print(f'Accuracy achieved by using the gini index: {accuracy_gini:.3f}')

Kodu Düzenle ve Çalıştır

Bu egzersiz

Python ile Ağaç Tabanlı Modellerle Machine Learning

kursunun bir parçasıdır

IntermediárioNível de habilidade

4.9+

Kursa Ücretsiz Başlayın

Classification and Regression Trees (CART) are a set of supervised learning models used for problems involving classification and regression. In this chapter, you'll be introduced to the CART algorithm.

Exercise 1: Sınıflandırma için karar ağacı Exercise 2: İlk sınıflandırma ağacını eğit Exercise 3: Sınıflandırma ağacını değerlendir Exercise 4: Lojistik regresyon vs sınıflandırma ağacı Exercise 5: Sınıflandırma ağacı öğrenimi Exercise 6: Bir sınıflandırma ağacını büyütme Exercise 7: Ölçüt olarak entropi kullanma Exercise 8: Entropi vs Gini indeksi

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Exercise 1: Generalization Error Exercise 2: Complexity, bias and variance Exercise 3: Overfitting and underfitting Exercise 4: Diagnose bias and variance problems Exercise 5: Instantiate the model Exercise 6: Evaluate the 10-fold CV error Exercise 7: Evaluate the training error Exercise 8: High bias or high variance?Exercise 9: Ensemble Learning Exercise 10: Define the ensemble Exercise 11: Evaluate individual classifiers Exercise 12: Better performance with a Voting Classifier

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Exercise 1: Bagging Exercise 2: Define the bagging classifier Exercise 3: Evaluate Bagging performance Exercise 4: Out of Bag Evaluation Exercise 5: Prepare the ground Exercise 6: OOB Score vs Test Set Score Exercise 7: Random Forests (RF)Exercise 8: Train an RF regressor Exercise 9: Evaluate the RF regressor Exercise 10: Visualizing features importances

Boosting refers to an ensemble method in which several models are trained sequentially with each model learning from the errors of its predecessors. In this chapter, you'll be introduced to the two boosting methods of AdaBoost and Gradient Boosting.

Exercise 1: Adaboost Exercise 2: Define the AdaBoost classifier Exercise 3: Train the AdaBoost classifier Exercise 4: Evaluate the AdaBoost classifier Exercise 5: Gradient Boosting (GB)Exercise 6: Define the GB regressor Exercise 7: Train the GB regressor Exercise 8: Evaluate the GB regressor Exercise 9: Stochastic Gradient Boosting (SGB)Exercise 10: Regression with SGB Exercise 11: Train the SGB regressor Exercise 12: Evaluate the SGB regressor

The hyperparameters of a machine learning model are parameters that are not learned from data. They should be set prior to fitting the model to the training set. In this chapter, you'll learn how to tune the hyperparameters of a tree-based model using grid search cross validation.

Exercise 1: Tuning a CART's Hyperparameters Exercise 2: Tree hyperparameters Exercise 3: Set the tree's hyperparameter grid Exercise 4: Search for the optimal tree Exercise 5: Evaluate the optimal tree Exercise 6: Tuning a RF's Hyperparameters Exercise 7: Random forests hyperparameters Exercise 8: Set the hyperparameter grid of RF Exercise 9: Search for the optimal forest Exercise 10: Evaluate the optimal forest Exercise 11: Congratulations!