DHSC-Capstone/ML/2-modeling.R
2023-02-02 20:50:30 -05:00

120 lines
3.1 KiB
R

rm(list = ls(all.names = TRUE)) # Clear the memory of variables from previous run.
cat("\014") # Clear the console
# load packages -----------------------------------------------------------
box::use(
magrittr[`%>%`]
,here[here]
,readr
,gp2 = ggplot2[ggplot, aes]
,rsample
,r = recipes
,wf = workflows
,p = parsnip[tune]
,ys = yardstick
,d = dials
,rsamp = rsample
)
# globals -----------------------------------------------------------------
set.seed(070823) #set seed for reproducible research
# load-data ---------------------------------------------------------------
model_data <- readr$read_rds(here("ML","data-unshared","model_data.RDS"))
# split data --------------------------------------------------------------
model_data_split <- rsample$initial_split(
model_data
,prop = 0.80
,strata = ft4_dia
)
ds_train <- rsample$training(model_data_split)
ds_test <- rsample$testing(model_data_split)
# verify distribution of data
table(ds_train$ft4_dia) %>% prop.table()
table(ds_test$ft4_dia) %>% prop.table()
class_train <- ds_train %>% dplyr::select(-FT4) # training data for classification models
reg_train <- ds_train %>% dplyr::select(-ft4_dia) # training data for reg models predicting result
# random forest classification -----------------------------------------------------------
# base model - No Hyper Tuning
rf__base_model <- p$rand_forest() %>%
p$set_engine("ranger") %>% p$set_mode("classification")
rf_recipe <- r$recipe(ft4_dia ~ . , data = class_train) %>%
r$update_role(subject_id, new_role = "id") %>%
r$update_role(charttime, new_role = "time") %>%
r$step_impute_bag(r$all_predictors())
rf_workflow <- wf$workflow() %>%
wf$add_model(rf__base_model) %>%
wf$add_recipe(rf_recipe)
rf_base_fit <- p$fit(rf_workflow, class_train)
rf_predict <- class_train %>%
dplyr::select(ft4_dia) %>%
dplyr::bind_cols(
predict(rf_base_fit, class_train)
,predict(rf_base_fit, class_train, type = "prob")
)
conf_mat_rf <- ys$conf_mat(rf_predict, ft4_dia, .pred_class)
rf_pred <- dplyr::select(class_train, -ft4_dia, -subject_id, -charttime)
rf_tuning_model <- p$rand_forest(trees = tune(), mtry = tune(), min_n = tune()) %>%
p$set_engine("ranger") %>% p$set_mode("classification")
rf_param <- p$extract_parameter_set_dials(rf_tuning_model)
rf_param <- rf_param %>% update(mtry = d$finalize(d$mtry(), rf_pred))
data_fold <- rsamp$vfold_cv(class_train, v = 5)
rf_workflow <- wf$update_model(rf_workflow, rf_tuning_model)
# takes around 1 hr to run grid search. saving best params manaually
# rf_tune <- rf_workflow %>%
# tune::tune_grid(
# data_fold
# ,grid = rf_param %>% d$grid_regular()
# )
rf_best_params <- tibble::tibble(
mtry = 8
,trees = 2000
,min_n = 2
)
final_rf_workflow <- rf_workflow %>%
tune::finalize_workflow(rf_best_params)
final_rf_fit <- p$fit(final_rf_workflow, class_train)
final_rf_predict <- class_train %>%
dplyr::select(ft4_dia) %>%
dplyr::bind_cols(
predict(final_rf_fit, class_train)
,predict(final_rf_fit, class_train, type = "prob")
)
final_conf_rf <- ys$conf_mat(final_rf_predict, ft4_dia, .pred_class)