Intro In Regork, there has been a concern for the amount of customers that are leaving the company. If the company cannot retain customers, there will be massive losses in revenue per month.

To determine what keeps customers with Regork, we decided to investigate the most important determinants for current customers. We used many different machine learnings to find the most significant predictor variables to the status of customers.

This analysis can be very beneficial for the company because it can save the company upwards of $36,000 in loss of revenue per month. Our solution is to encourage new customers to sign longer contracts, and making sure customers are happy with the company’s services.

Data Preparation & Exploratory Data Analysis

library(tidymodels)
library(tidyverse)
library(baguette)
library(vip)
library(pdp)
library(readr)
library(ggplot2)
library(rpart.plot)
library(ranger)
library(gmodels)
library(ROCR)
library(VIM)
library(corrplot)
library(randomForest)
library(caTools)
cr1 <- read.csv("customer_retention.csv")

cr1 <- read_csv("customer_retention.csv")

cr <- mutate(cr1, Status = factor(Status)) %>% na.omit()
cr %>% 
  count(Status) %>% 
  mutate(prop = n / sum(n)) 
## # A tibble: 2 × 3
##   Status      n  prop
##   <fct>   <int> <dbl>
## 1 Current  5132 0.734
## 2 Left     1856 0.266
cr %>% 
  group_by(Status) %>% 
  summarise(Number = n()) %>%
  mutate(Percent = prop.table(Number)*100) %>% 
  ggplot(aes(Status, Percent)) + 
  geom_col(aes(fill = Status)) +
  labs(title = "Percentage by Status") +
  theme(plot.title = element_text(hjust = 0.5)) +
  geom_text(aes(label = sprintf("%.1f%%", Percent))) 

p1<- ggplot(data = cr, aes(x = PhoneService, y = MonthlyCharges, fill = PhoneService))+geom_boxplot()

p2<- ggplot(data = cr, aes(x = PhoneService, y = TotalCharges, fill = PhoneService))+geom_boxplot()

grid.arrange(p1, p2, ncol=2)

p3 <- ggplot(data = cr, aes(x = Contract, y = MonthlyCharges, fill = Contract))+geom_boxplot() + stat_summary(fun=mean, geom="point", shape=20, size=8, color="red", fill="red")

 
p4 <- ggplot(data = cr, aes(x = Contract, y = TotalCharges, fill = Contract))+geom_boxplot() + stat_summary(fun=mean, geom="point", shape=20, size=8, color="red", fill="red") 

p5 <- ggplot(data = cr, aes(x = Contract, y = Tenure, fill = Contract))+geom_boxplot() + stat_summary(fun=mean, geom="point", shape=20, size=8, color="red", fill="red")

grid.arrange(p3, p4, p5, ncol=2)

p6 <- ggplot(data = cr, aes(x = factor(Status), y = Tenure, fill = Status)) +geom_boxplot()

p7 <- ggplot(data = cr, aes(x = factor(Status), y = MonthlyCharges, fill = Status))+geom_boxplot()

p8 <- ggplot(data = cr, aes(x = factor(Status), y = TotalCharges, fill = Status))+geom_boxplot()

grid.arrange(p6, p7, p8, ncol=2)

ggplot(data = cr, aes(x=Tenure, fill = factor(Status))) + geom_bar(position = "fill") + scale_fill_manual(values = c("blue", "red")) + theme(
  plot.background = element_blank(),
  panel.grid.major = element_blank(),
  panel.grid.minor = element_blank(),
  panel.border = element_blank(),
  plot.title = element_text(hjust = 0.5),
  text=element_text(size=14,  family="Helvetica")) + labs(x = " ", title = "Status by Tenure")

ggplot(data = cr, aes(x=Contract, fill = factor(Status)))+ geom_bar(position = "fill") + scale_fill_manual(values = c("blue", "red")) + theme(
  plot.background = element_blank(),
  panel.grid.major = element_blank(),
  panel.grid.minor = element_blank(),
  panel.border = element_blank(),
  plot.title = element_text(hjust = 0.5),
  text=element_text(size=14,  family="Helvetica")) + labs(x = " ", title = "Status by Contract type") + coord_flip()

ggplot(data = cr, aes(x=factor(SeniorCitizen), fill = factor(Status)))+ geom_bar(position = "fill") + scale_fill_manual(values = c("blue", "red")) + theme(
  plot.background = element_blank(),
  panel.grid.major = element_blank(),
  panel.grid.minor = element_blank(),
  panel.border = element_blank(),
  plot.title = element_text(hjust = 0.5),
  text=element_text(size=14,  family="Helvetica")) + labs(x = " ", title = "Non-Senior vs Senior citizen")

ggplot(data = cr, aes(x=PaperlessBilling, fill = factor(Status))) + geom_bar(position = "fill") + scale_fill_manual(values = c("blue", "red")) + theme(
  plot.background = element_blank(),
  panel.grid.major = element_blank(),
  panel.grid.minor = element_blank(),
  panel.border = element_blank(),
  plot.title = element_text(hjust = 0.5),
  text=element_text(size=14,  family="Helvetica")) + labs(x = " ", title = "Status by having paperless billing")

ggplot(data = cr, aes(x=PaymentMethod, fill = factor(Status))) + geom_bar(position = "fill") + scale_fill_manual(values = c("blue", "red")) + theme(
  plot.background = element_blank(),
  panel.grid.major = element_blank(),
  panel.grid.minor = element_blank(),
  panel.border = element_blank(),
  plot.title = element_text(hjust = 0.5),
  text=element_text(size=12,  family="Helvetica")) + labs(x = "", title = "Status by Payment Method") + coord_flip() 

ggplot(data = cr, aes(x=Partner, fill = factor(Status))) + geom_bar(position = "fill") + scale_fill_manual(values = c("blue", "red")) + theme(
  plot.background = element_blank(),
  panel.grid.major = element_blank(),
  panel.grid.minor = element_blank(),
  panel.border = element_blank(),
  plot.title = element_text(hjust = 0.5),
  text=element_text(size=12,  family="Helvetica")) + labs(x = " ", title = "Status by having a partner") 

ggplot(data = cr, aes(x=Dependents, fill = factor(Status))) + geom_bar(position = "fill") + scale_fill_manual(values = c("blue", "red")) + theme(
  plot.background = element_blank(),
  panel.grid.major = element_blank(),
  panel.grid.minor = element_blank(),
  panel.border = element_blank(),
  plot.title = element_text(hjust = 0.5),
  text=element_text(size=12,  family="Helvetica")) + labs(x = " ", title = "Status by having dependents") + coord_flip() 

ggplot(data = cr, aes(x=InternetService, fill = factor(Status))) + geom_bar(position = "fill") + scale_fill_manual(values = c("blue", "red")) + theme(
  plot.background = element_blank(),
  panel.grid.major = element_blank(),
  panel.grid.minor = element_blank(),
  panel.border = element_blank(),
  plot.title = element_text(hjust = 0.5),
  text=element_text(size=12,  family="Helvetica")) + labs(x = " ", title = "Status by Internet service") + coord_flip() 

p9 <- ggplot(data = cr, aes(x=OnlineSecurity, fill = factor(Status))) + geom_bar(position = "fill") + coord_flip() + labs(title = "Online security")

p10 <- ggplot(data = cr, aes(x=OnlineBackup, fill = factor(Status))) + geom_bar(position = "fill") + coord_flip() + labs(title = "Online backup")

p11 <- ggplot(data = cr, aes(x=DeviceProtection, fill = factor(Status))) + geom_bar(position = "fill") + coord_flip() + labs(title = "Device protection")

p12 <- ggplot(data = cr, aes(x=TechSupport, fill = factor(Status))) + geom_bar(position = "fill") + coord_flip() + labs(title = "Tech support")

grid.arrange(p9, p10, p11, p12,nrow=2 )

ggplot(data = cr, aes(x=MonthlyCharges, y=Tenure, color=factor(Status))) + geom_point(alpha = 0.5) + geom_smooth(method=lm) + labs(title = " ")

ggplot(data = cr, aes(x=TotalCharges, y=Tenure, color=factor(Status))) + geom_point(alpha = 0.5) +geom_smooth(method=lm) + scale_x_log10() + labs(title = "Log transformation")

set.seed(123) 

cr_split <- initial_split(cr, prop = .7, strata = "Status") 

cr_train <- training(cr_split) 

cr_test  <- testing(cr_split) 



cr_train %>% 
  
  count(Status) %>% 
  
  mutate(prop = n / sum(n)) 
## # A tibble: 2 × 3
##   Status      n  prop
##   <fct>   <int> <dbl>
## 1 Current  3592 0.734
## 2 Left     1299 0.266
cr_test %>% 
  
  count(Status) %>% 
  
  mutate(prop = n / sum(n)) 
## # A tibble: 2 × 3
##   Status      n  prop
##   <fct>   <int> <dbl>
## 1 Current  1540 0.734
## 2 Left      557 0.266
set.seed(123) 

kfold <- vfold_cv(cr_train, v = 5) 



lr_mod <- logistic_reg() 



results <- lr_mod %>% 
  
  fit_resamples(Status ~ ., kfold) 



collect_metrics(results) %>% filter(.metric == "accuracy") 
## # A tibble: 1 × 6
##   .metric  .estimator  mean     n std_err .config             
##   <chr>    <chr>      <dbl> <int>   <dbl> <chr>               
## 1 accuracy binary     0.797     5 0.00705 Preprocessor1_Model1
show_best(results, metric = "roc_auc") 
## # A tibble: 1 × 6
##   .metric .estimator  mean     n std_err .config             
##   <chr>   <chr>      <dbl> <int>   <dbl> <chr>               
## 1 roc_auc binary     0.844     5 0.00974 Preprocessor1_Model1
show_best(results, metric = "roc_auc") 
## # A tibble: 1 × 6
##   .metric .estimator  mean     n std_err .config             
##   <chr>   <chr>      <dbl> <int>   <dbl> <chr>               
## 1 roc_auc binary     0.844     5 0.00974 Preprocessor1_Model1
final_fit <- lr_mod %>% 
  fit(Status ~ ., data = cr_train) 

tidy(final_fit) 
## # A tibble: 31 × 5
##    term                          estimate std.error statistic   p.value
##    <chr>                            <dbl>     <dbl>     <dbl>     <dbl>
##  1 (Intercept)                     1.02     0.969      1.05    2.95e- 1
##  2 GenderMale                     -0.0461   0.0779    -0.592   5.54e- 1
##  3 SeniorCitizen                   0.258    0.101      2.55    1.08e- 2
##  4 PartnerYes                     -0.141    0.0925    -1.52    1.29e- 1
##  5 DependentsYes                  -0.0475   0.108     -0.441   6.59e- 1
##  6 Tenure                         -0.0646   0.00762   -8.47    2.35e-17
##  7 PhoneServiceYes                -0.0417   0.774     -0.0539  9.57e- 1
##  8 MultipleLinesNo phone service  NA       NA         NA      NA       
##  9 MultipleLinesYes                0.442    0.211      2.10    3.56e- 2
## 10 InternetServiceFiber optic      1.48     0.950      1.56    1.18e- 1
## # … with 21 more rows
exp(coef(final_fit$fit)) 
##                          (Intercept)                           GenderMale 
##                            2.7593894                            0.9549166 
##                        SeniorCitizen                           PartnerYes 
##                            1.2949103                            0.8688686 
##                        DependentsYes                               Tenure 
##                            0.9536487                            0.9374419 
##                      PhoneServiceYes        MultipleLinesNo phone service 
##                            0.9591253                                   NA 
##                     MultipleLinesYes           InternetServiceFiber optic 
##                            1.5562922                            4.4143178 
##                    InternetServiceNo    OnlineSecurityNo internet service 
##                            0.2214383                                   NA 
##                    OnlineSecurityYes      OnlineBackupNo internet service 
##                            0.7591602                                   NA 
##                      OnlineBackupYes  DeviceProtectionNo internet service 
##                            0.9028811                                   NA 
##                  DeviceProtectionYes       TechSupportNo internet service 
##                            1.1801326                                   NA 
##                       TechSupportYes       StreamingTVNo internet service 
##                            0.8583097                                   NA 
##                       StreamingTVYes   StreamingMoviesNo internet service 
##                            1.6073481                                   NA 
##                   StreamingMoviesYes                     ContractOne year 
##                            1.7542279                            0.4452648 
##                     ContractTwo year                  PaperlessBillingYes 
##                            0.2497494                            1.3698551 
## PaymentMethodCredit card (automatic)        PaymentMethodElectronic check 
##                            1.0223826                            1.3813743 
##            PaymentMethodMailed check                       MonthlyCharges 
##                            0.9410159                            0.9689548 
##                         TotalCharges 
##                            1.0003906
final_fit %>% 
  
  predict(cr_test) %>% 
  
  bind_cols(cr_test %>% select(Status)) %>% 
  
  conf_mat(truth = Status, estimate = .pred_class) 
##           Truth
## Prediction Current Left
##    Current    1362  225
##    Left        178  332
vip::vip(final_fit) 

lr_fit1 <- lr_mod %>%  
  
  fit(Status ~ MonthlyCharges, data = cr_train) 



lr_fit1 %>% predict(cr_train, type = "prob") 
## # A tibble: 4,891 × 2
##    .pred_Current .pred_Left
##            <dbl>      <dbl>
##  1         0.836      0.164
##  2         0.768      0.232
##  3         0.807      0.193
##  4         0.836      0.164
##  5         0.787      0.213
##  6         0.604      0.396
##  7         0.574      0.426
##  8         0.855      0.145
##  9         0.599      0.401
## 10         0.661      0.339
## # … with 4,881 more rows

Machine Learning

Logistic Regression

p1 <- lr_fit1 %>%  
  
  predict(cr_train, type = "prob") %>% 
  
  mutate(MonthlyCharges = cr_train$MonthlyCharges) %>% 
  
  ggplot(aes(MonthlyCharges, .pred_Left)) + 
  
  geom_point(alpha = .2, color = "orange") + 
  
  scale_y_continuous("Probability of Leaving", limits = c(0, 1)) + 
  
  ggtitle("Predicted Probabilities Regarding Monthly Charges") + 
  
  theme_classic() 

p1 

exp(coef(lr_fit1$fit)) 
##    (Intercept) MonthlyCharges 
##      0.1216563      1.0160933
lr_fit2 <- lr_mod %>%  
  
  fit(Status ~ MonthlyCharges + SeniorCitizen, data = cr_train) 



lr_fit2 %>% predict(cr_train, type = "prob") 
## # A tibble: 4,891 × 2
##    .pred_Current .pred_Left
##            <dbl>      <dbl>
##  1         0.843      0.157
##  2         0.785      0.215
##  3         0.818      0.182
##  4         0.843      0.157
##  5         0.801      0.199
##  6         0.647      0.353
##  7         0.622      0.378
##  8         0.859      0.141
##  9         0.643      0.357
## 10         0.696      0.304
## # … with 4,881 more rows
p2 <- lr_fit2 %>%  
  
  predict(cr_train, type = "prob") %>% 
  
  mutate(MonthlyCharges = cr_train$MonthlyCharges,  
         
         SeniorCitizen = cr_train$SeniorCitizen) %>% 
  
  ggplot(aes(MonthlyCharges, .pred_Left, color = SeniorCitizen)) + 
  
  geom_point(alpha = .2, size = 1.5) + 
  
  scale_y_continuous("Probability of Leaving", limits = c(0, 1)) + 
  
  ggtitle("Predicted Probabilities Regarding Monthly Charges")  + 
  
  theme_classic() 



p2 

lr_fit3 <- lr_mod %>%  
  
  fit(Status ~ TotalCharges + SeniorCitizen, data = cr_train) 



p3 <- lr_fit3 %>%  
  
  predict(cr_train, type = "prob") %>% 
  
  mutate(TotalCharges = cr_train$TotalCharges,  
         
         SeniorCitizen = cr_train$SeniorCitizen) %>% 
  
  ggplot(aes(TotalCharges, .pred_Left, color = SeniorCitizen)) + 
  
  geom_point(alpha = .2, size = 1.5) + 
  
  scale_y_continuous("Probability of Leaving", limits = c(0, 1)) + 
  
  ggtitle("Predicted Probabilities Regarding Total Charges")  + 
  
  theme_classic() 

p3 

lr_fit4 <- lr_mod %>%  
  
  fit(Status ~ TotalCharges, data = cr_train) 



p4 <- lr_fit4 %>%  
  
  predict(cr_train, type = "prob") %>% 
  
  mutate(TotalCharges = cr_train$TotalCharges) %>% 
  
  ggplot(aes(TotalCharges, .pred_Left)) + 
  
  geom_point(alpha = .2, color = "orange") + 
  
  scale_y_continuous("Probability of Leaving", limits = c(0, 1)) + 
  
  ggtitle("Predicted Probabilities Regarding Total Charges") + 
  
  theme_classic() 

p4 

lr_fit5 <- lr_mod %>%  
  
  fit(Status ~ MonthlyCharges + Tenure, data = cr_train) 



p5 <- lr_fit5 %>%  
  
  predict(cr_train, type = "prob") %>% 
  
  mutate(MonthlyCharges = cr_train$MonthlyCharges,  
         
         Tenure = cr_train$Tenure) %>% 
  
  ggplot(aes(MonthlyCharges, .pred_Left, color = Tenure)) + 
  
  geom_point(alpha = .2, size = 1.5) + 
  
  scale_y_continuous("Probability of Leaving", limits = c(0, 1)) + 
  
  ggtitle("Predicted Probabilities Regarding Monthly Charges")  + 
  
  theme_classic() 

p5 

lr_fit6 <- lr_mod %>%  
  
  fit(Status ~ MonthlyCharges + Gender, data = cr_train) 



p6 <- lr_fit6 %>%  
  
  predict(cr_train, type = "prob") %>% 
  
  mutate(MonthlyCharges = cr_train$MonthlyCharges,  
         
         Gender = cr_train$Gender) %>% 
  
  ggplot(aes(MonthlyCharges, .pred_Left, color = Gender)) + 
  
  geom_point(alpha = .2, size = .8) + 
  
  scale_y_continuous("Probability of Leaving", limits = c(0, 1)) + 
  
  ggtitle("Predicted Probabilities Regarding Monthly Charges")  + 
  
  theme_classic() 

p6 

lr_fit7 <- lr_mod %>%  
  
  fit(Status ~ MonthlyCharges + Partner, data = cr_train) 



p7 <- lr_fit7 %>%  
  
  predict(cr_train, type = "prob") %>% 
  
  mutate(MonthlyCharges = cr_train$MonthlyCharges,  
         
         Partner = cr_train$Partner) %>% 
  
  ggplot(aes(MonthlyCharges, .pred_Left, color = Partner)) + 
  
  geom_point(alpha = .2, size = .8) + 
  
  scale_y_continuous("Probability of Leaving", limits = c(0, 1)) + 
  
  ggtitle("Predicted Probabilities Regarding Monthly Charges")  + 
  
  theme_classic() 

p7 

lr_fit8 <- lr_mod %>%  
  
  fit(Status ~ MonthlyCharges + Dependents, data = cr_train) 



p8 <- lr_fit8 %>%  
  
  predict(cr_train, type = "prob") %>% 
  
  mutate(MonthlyCharges = cr_train$MonthlyCharges,  
         
         Dependents = cr_train$Dependents) %>% 
  
  ggplot(aes(MonthlyCharges, .pred_Left, color = Dependents)) + 
  
  geom_point(alpha = .2, size = .8) + 
  
  scale_y_continuous("Probability of Leaving", limits = c(0, 1)) + 
  
  ggtitle("Predicted Probabilities Regarding Monthly Charges")  + 
  
  theme_classic() 

p8 

lr_fit9 <- lr_mod %>%  
  
  fit(Status ~ MonthlyCharges + Dependents + Partner +  
        
        SeniorCitizen + Gender, data = cr_train) 



lr_fit9 %>% 
  
  predict(cr_test) %>% 
  
  bind_cols(cr_test %>% select(Status)) %>% 
  
  accuracy(truth = Status, estimate = .pred_class) 
## # A tibble: 1 × 3
##   .metric  .estimator .estimate
##   <chr>    <chr>          <dbl>
## 1 accuracy binary         0.727
lr_fit10 <- lr_mod %>%  
  
  fit(Status ~ ., data = cr_train) 



lr_fit10 %>% 
  
  predict(cr_test) %>% 
  
  bind_cols(cr_test %>% select(Status)) %>% 
  
  accuracy(truth = Status, estimate = .pred_class) 
## # A tibble: 1 × 3
##   .metric  .estimator .estimate
##   <chr>    <chr>          <dbl>
## 1 accuracy binary         0.808
exp(coef(lr_fit10$fit)) 
##                          (Intercept)                           GenderMale 
##                            2.7593894                            0.9549166 
##                        SeniorCitizen                           PartnerYes 
##                            1.2949103                            0.8688686 
##                        DependentsYes                               Tenure 
##                            0.9536487                            0.9374419 
##                      PhoneServiceYes        MultipleLinesNo phone service 
##                            0.9591253                                   NA 
##                     MultipleLinesYes           InternetServiceFiber optic 
##                            1.5562922                            4.4143178 
##                    InternetServiceNo    OnlineSecurityNo internet service 
##                            0.2214383                                   NA 
##                    OnlineSecurityYes      OnlineBackupNo internet service 
##                            0.7591602                                   NA 
##                      OnlineBackupYes  DeviceProtectionNo internet service 
##                            0.9028811                                   NA 
##                  DeviceProtectionYes       TechSupportNo internet service 
##                            1.1801326                                   NA 
##                       TechSupportYes       StreamingTVNo internet service 
##                            0.8583097                                   NA 
##                       StreamingTVYes   StreamingMoviesNo internet service 
##                            1.6073481                                   NA 
##                   StreamingMoviesYes                     ContractOne year 
##                            1.7542279                            0.4452648 
##                     ContractTwo year                  PaperlessBillingYes 
##                            0.2497494                            1.3698551 
## PaymentMethodCredit card (automatic)        PaymentMethodElectronic check 
##                            1.0223826                            1.3813743 
##            PaymentMethodMailed check                       MonthlyCharges 
##                            0.9410159                            0.9689548 
##                         TotalCharges 
##                            1.0003906
cr_recipe <- recipe(Status ~ ., data = cr_train) 



cr_std <- cr_recipe %>% 
  
  step_normalize(all_numeric_predictors()) %>% 
  
  step_YeoJohnson(all_numeric_predictors())

Decision Tree

set.seed(123)
churn_split <- initial_split(cr,prop = 0.7, strata = "Status")
churn_train <- training(churn_split)
churn_test <- testing(churn_split)

dt_mod <- decision_tree(mode = 'classification') %>%
  set_engine("rpart")

model_recipe <- recipe(Status ~ ., data = cr)

dt_fit <- workflow() %>%
  add_recipe(model_recipe) %>%
  add_model(dt_mod) %>%
  fit(data = cr)

rpart.plot::rpart.plot(dt_fit$fit$fit$fit)

set.seed(123)
kfold <- vfold_cv(cr, v = 5)

dt_results <- fit_resamples(dt_mod, model_recipe, kfold)

collect_metrics(dt_results)
## # A tibble: 2 × 6
##   .metric  .estimator  mean     n std_err .config             
##   <chr>    <chr>      <dbl> <int>   <dbl> <chr>               
## 1 accuracy binary     0.787     5 0.00447 Preprocessor1_Model1
## 2 roc_auc  binary     0.802     5 0.00532 Preprocessor1_Model1
dt_mod <- decision_tree(
  mode = "classification",
  cost_complexity = tune(),
  tree_depth = tune(),
  min_n = tune()
) %>%
  set_engine("rpart")

dt_hyper_grid <- grid_regular(
  cost_complexity(),
  tree_depth(),
  min_n(),
  levels = 5
)
set.seed(123)
dt_results <- tune_grid(dt_mod, model_recipe, resamples = kfold, grid = dt_hyper_grid)

show_best(dt_results, metric = "roc_auc", n = 5)
## # A tibble: 5 × 9
##   cost_complexity tree_depth min_n .metric .estima…¹  mean     n std_err .config
##             <dbl>      <int> <int> <chr>   <chr>     <dbl> <int>   <dbl> <chr>  
## 1    0.0000000001          8    21 roc_auc binary    0.820     5 0.00698 Prepro…
## 2    0.0000000178          8    21 roc_auc binary    0.820     5 0.00698 Prepro…
## 3    0.00000316            8    21 roc_auc binary    0.820     5 0.00698 Prepro…
## 4    0.0000000001          8    30 roc_auc binary    0.819     5 0.00741 Prepro…
## 5    0.0000000178          8    30 roc_auc binary    0.819     5 0.00741 Prepro…
## # … with abbreviated variable name ¹​.estimator
dt_best_model <- select_best(dt_results, metric = 'roc_auc')

dt_final_wf <- workflow() %>%
  add_recipe(model_recipe) %>%
  add_model(dt_mod) %>%
  finalize_workflow(dt_best_model)

dt_final_fit <- dt_final_wf %>%
  fit(data = cr)

dt_final_fit %>%
  extract_fit_parsnip() %>%
  vip(20)

bag_mod <- bag_tree() %>%
  set_engine("rpart", times = 5) %>%
  set_mode("classification")

bag_results <- fit_resamples(bag_mod, model_recipe, kfold)

collect_metrics(bag_results)
## # A tibble: 2 × 6
##   .metric  .estimator  mean     n std_err .config             
##   <chr>    <chr>      <dbl> <int>   <dbl> <chr>               
## 1 accuracy binary     0.759     5 0.00551 Preprocessor1_Model1
## 2 roc_auc  binary     0.759     5 0.00597 Preprocessor1_Model1
kfold <- vfold_cv(churn_train, v = 5)

collect_metrics(dt_results)
## # A tibble: 250 × 9
##    cost_complexity tree_depth min_n .metric  .esti…¹  mean     n std_err .config
##              <dbl>      <int> <int> <chr>    <chr>   <dbl> <int>   <dbl> <chr>  
##  1    0.0000000001          1     2 accuracy binary  0.734     5 0.00564 Prepro…
##  2    0.0000000001          1     2 roc_auc  binary  0.5       5 0       Prepro…
##  3    0.0000000178          1     2 accuracy binary  0.734     5 0.00564 Prepro…
##  4    0.0000000178          1     2 roc_auc  binary  0.5       5 0       Prepro…
##  5    0.00000316            1     2 accuracy binary  0.734     5 0.00564 Prepro…
##  6    0.00000316            1     2 roc_auc  binary  0.5       5 0       Prepro…
##  7    0.000562              1     2 accuracy binary  0.734     5 0.00564 Prepro…
##  8    0.000562              1     2 roc_auc  binary  0.5       5 0       Prepro…
##  9    0.1                   1     2 accuracy binary  0.734     5 0.00564 Prepro…
## 10    0.1                   1     2 roc_auc  binary  0.5       5 0       Prepro…
## # … with 240 more rows, and abbreviated variable name ¹​.estimator
dt_mod <- decision_tree(
  mode = "classification",
  cost_complexity = tune(),
  tree_depth = tune(),
  min_n = tune()
) %>%
  set_engine("rpart")

dt_hyper_grid <- grid_regular(
  cost_complexity(),
  tree_depth(),
  min_n(),
  levels = 5
)
set.seed(123)
dt_results <- tune_grid(dt_mod, model_recipe, resamples = kfold, grid = dt_hyper_grid)

show_best(dt_results, metric = "roc_auc", n = 5)
## # A tibble: 5 × 9
##   cost_complexity tree_depth min_n .metric .estima…¹  mean     n std_err .config
##             <dbl>      <int> <int> <chr>   <chr>     <dbl> <int>   <dbl> <chr>  
## 1    0.0000000001          8    30 roc_auc binary    0.823     5 0.00705 Prepro…
## 2    0.0000000178          8    30 roc_auc binary    0.823     5 0.00705 Prepro…
## 3    0.00000316            8    30 roc_auc binary    0.823     5 0.00705 Prepro…
## 4    0.0000000001          8    40 roc_auc binary    0.821     5 0.00764 Prepro…
## 5    0.0000000178          8    40 roc_auc binary    0.821     5 0.00764 Prepro…
## # … with abbreviated variable name ¹​.estimator
best_model <- select_best(dt_results, metric = 'roc_auc')

final_wf <- workflow() %>%
  add_recipe(model_recipe) %>%
  add_model(dt_mod) %>%
  finalize_workflow(best_model)

final_fit <- final_wf %>%
  fit(data = churn_train)

final_fit %>%
  extract_fit_parsnip() %>%
  vip(20)

Random Forest

set.seed(123)
split <- initial_split(cr, prop = 0.7, strata = "Status")
train <- training(split)
test <- testing(split)

model_recipe <- recipe(Status ~ ., data = train)

rf_mod <- rand_forest(
  mode = "classification",
  trees = tune(),
  mtry = tune(),
  min_n = tune()
) %>%
  set_engine("ranger", importance = "impurity")

rf_hyper_grid <- grid_regular(
  trees(range = c(50,200)),
  mtry(range = c(4,50)),
  min_n(range = c(4,20)),
  levels = 5)
set.seed(123)

kfold <- vfold_cv(train, v = 5, strata = Status)

rf_results <- tune_grid(rf_mod, model_recipe, resamples = kfold, grid = rf_hyper_grid)

show_best(rf_results, metric = "roc_auc")
## # A tibble: 5 × 9
##    mtry trees min_n .metric .estimator  mean     n std_err .config              
##   <int> <int> <int> <chr>   <chr>      <dbl> <int>   <dbl> <chr>                
## 1     4   200    20 roc_auc binary     0.842     5 0.00474 Preprocessor1_Model1…
## 2     4   125    20 roc_auc binary     0.841     5 0.00456 Preprocessor1_Model1…
## 3     4   125    16 roc_auc binary     0.841     5 0.00449 Preprocessor1_Model0…
## 4     4   162    20 roc_auc binary     0.841     5 0.00479 Preprocessor1_Model1…
## 5     4    87    20 roc_auc binary     0.841     5 0.00482 Preprocessor1_Model1…
rf_best_hyperparameters <- select_best(rf_results, metric = "roc_auc")
final_rf_wf <- workflow() %>%
  add_recipe(model_recipe) %>%
  add_model(rf_mod) %>%
  finalize_workflow(rf_best_hyperparameters)

rf_final_fit <- final_rf_wf %>%
  fit(data = train)

rf_final_fit %>%
  predict(test) %>%
  bind_cols(test %>% select(Status)) %>%
  conf_mat(truth = "Status", estimate = .pred_class)
##           Truth
## Prediction Current Left
##    Current    1387  266
##    Left        153  291
rf_final_fit %>%
  extract_fit_parsnip() %>%
  vip(num_features = 10)