Another round of pruning based on AUC
In the video you saw how the "full" logistic regression model with a logit link was being pruned based on the AUC. You saw how the variable home_ownership was deleted from the model, as it improved the overall AUC. After repeating this process for two additional rounds, the variables age and ir_cat were deleted, leading to the model:
log_3_remove_ir <- glm(loan_status ~ loan_amnt + grade + annual_inc + emp_cat, family = binomial, data = training_set)
with an AUC of 0.6545. Now, it's your turn to see whether the AUC can still be improved by deleting another variable from the model.
แบบฝึกหัดนี้เป็นส่วนหนึ่งของหลักสูตร
Credit Risk Modeling in R
คำแนะนำการฝึกหัด
- Delete one variable at a time in the model
log_3_remove_ir, Remember that you should be using the default link function (logit). - Make probability of default-predictions for each of the models you created.
- Use function
auc()usingtest_set$loan_statusas a first argument and the predictions for each of the four models as a second argument to obtain the AUC's for each model. - Copy the name of the object (as given in the first question of this exercise) that represents the model with the best AUC.
แบบฝึกหัดเชิงโต้ตอบแบบลงมือทำ
ลองทำแบบฝึกหัดนี้โดยเติมโค้ดตัวอย่างนี้ให้สมบูรณ์
# Build four models each time deleting one variable in log_3_remove_ir
log_4_remove_amnt <- glm(loan_status ~ grade + annual_inc + emp_cat,
family = binomial, data = training_set)
log_4_remove_grade <-
log_4_remove_inc <-
log_4_remove_emp <-
# Make PD-predictions for each of the models
pred_4_remove_amnt <- predict(log_4_remove_amnt, newdata = test_set, type = "response")
pred_4_remove_grade <-
pred_4_remove_inc <-
pred_4_remove_emp <-
# Compute the AUCs