k-Nearest Neighbors: Fit

In questo esercizio costruirai il tuo primo modello di classificazione utilizzando il dataset churn_df, che è stato precaricato per il resto del capitolo.

L'obiettivo, "churn", deve essere una singola colonna con lo stesso numero di osservazioni dei dati delle caratteristiche. I dati delle caratteristiche sono già stati convertiti in array numpy.

"account_length" e "customer_service_calls" sono trattati come caratteristiche perché la lunghezza dell'account indica la fedeltà del cliente e le frequenti chiamate al servizio clienti possono segnalare l'insoddisfazione, entrambi fattori che possono essere buoni predittori di abbandono.

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Apprendimento supervisionato con scikit-learn

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Istruzioni dell'esercizio

Importa KNeighborsClassifier da sklearn.neighbors.
Istanziare un KNeighborsClassifier chiamato knn con 6 vicini.
Adatta il classificatore ai dati utilizzando il metodo .fit().

Esercizio pratico interattivo

Prova a risolvere questo esercizio completando il codice di esempio.

# Import KNeighborsClassifier
from ____.____ import ____ 

y = churn_df["churn"].values
X = churn_df[["account_length", "customer_service_calls"]].values

# Create a KNN classifier with 6 neighbors
knn = ____(____=____)

# Fit the classifier to the data
knn.____(____, ____)

Modifica ed esegui il codice

Questo esercizio fa parte del corso

Apprendimento supervisionato con scikit-learn

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In this chapter, you'll be introduced to classification problems and learn how to solve them using supervised learning techniques. You'll learn how to split data into training and test sets, fit a model, make predictions, and evaluate accuracy. You’ll discover the relationship between model complexity and performance, applying what you learn to a churn dataset, where you will classify the churn status of a telecom company's customers.

Exercise 1: Apprendimento automatico con scikit-learn Exercise 2: Classificazione binaria Exercise 3: Il flusso di lavoro dell'apprendimento supervisionato Exercise 4: La sfida della classificazione Exercise 5: k-Nearest Neighbors: Fit

Esercizio in corso

Exercise 6: k-Nearest Neighbors: Prevedere Exercise 7: Misurare le prestazioni del modello Exercise 8: Divisione treno/test + calcolo dell'accuratezza Exercise 9: Overfitting e underfitting Exercise 10: Visualizzazione della complessità del modello

In this chapter, you will be introduced to regression, and build models to predict sales values using a dataset on advertising expenditure. You will learn about the mechanics of linear regression and common performance metrics such as R-squared and root mean squared error. You will perform k-fold cross-validation, and apply regularization to regression models to reduce the risk of overfitting.

Exercise 1: Introduction to regression Exercise 2: Creating features Exercise 3: Building a linear regression model Exercise 4: Visualizing a linear regression model Exercise 5: The basics of linear regression Exercise 6: Fit and predict for regression Exercise 7: Regression performance Exercise 8: Cross-validation Exercise 9: Cross-validation for R-squared Exercise 10: Analyzing cross-validation metrics Exercise 11: Regularized regression Exercise 12: Regularized regression: Ridge Exercise 13: Lasso regression for feature importance

Having trained models, now you will learn how to evaluate them. In this chapter, you will be introduced to several metrics along with a visualization technique for analyzing classification model performance using scikit-learn. You will also learn how to optimize classification and regression models through the use of hyperparameter tuning.

Exercise 1: How good is your model?Exercise 2: Deciding on a primary metric Exercise 3: Assessing a diabetes prediction classifier Exercise 4: Logistic regression and the ROC curve Exercise 5: Building a logistic regression model Exercise 6: The ROC curve Exercise 7: ROC AUC Exercise 8: Hyperparameter tuning Exercise 9: Hyperparameter tuning with GridSearchCV Exercise 10: Hyperparameter tuning with RandomizedSearchCV

Learn how to impute missing values, convert categorical data to numeric values, scale data, evaluate multiple supervised learning models simultaneously, and build pipelines to streamline your workflow!

Exercise 1: Preprocessing data Exercise 2: Creating dummy variables Exercise 3: Regression with categorical features Exercise 4: Handling missing data Exercise 5: Dropping missing data Exercise 6: Pipeline for song genre prediction: I Exercise 7: Pipeline for song genre prediction: II Exercise 8: Centering and scaling Exercise 9: Centering and scaling for regression Exercise 10: Centering and scaling for classification Exercise 11: Evaluating multiple models Exercise 12: Visualizing regression model performance Exercise 13: Predicting on the test set Exercise 14: Visualizing classification model performance Exercise 15: Pipeline for predicting song popularity Exercise 16: Congratulations