The goal of scorecard package is to make the development of the traditional credit risk scorecard model easier and efficient by providing functions for some common tasks that summarized in below. This package can also used in the development of machine learning models on binary classification.
- data preprocessing (
split_df,replace_na,one_hot,var_scale) - weight of evidence (woe) binning (
woebin,woebin_plot,woebin_adj,woebin_ply) - variable selection (
var_filter,iv,vif) - performance evaluation (
perf_eva,perf_cv,perf_psi) - scorecard scaling (
scorecard,scorecard2,scorecard_ply) - scorecard report (
gains_table,report)
Installation
- Install the release version of
scorecardfrom CRAN with:
install.packages("scorecard")
- Install the latest version of
scorecardfrom github with:
# install.packages("devtools") devtools::install_github("shichenxie/scorecard")
Example
This is a basic example which shows you how to develop a common credit risk scorecard:
# Traditional Credit Scoring Using Logistic Regression library(scorecard) # data preparing ------ # load germancredit data data("germancredit") # filter variable via missing rate, iv, identical value rate dt_f = var_filter(germancredit, y="creditability") # breaking dt into train and test dt_list = split_df(dt_f, y="creditability", ratios = c(0.6, 0.4), seed = 30) label_list = lapply(dt_list, function(x) x$creditability) # woe binning ------ bins = woebin(dt_f, y="creditability") # woebin_plot(bins) # binning adjustment ## adjust breaks interactively # breaks_adj = woebin_adj(dt_f, "creditability", bins) ## or specify breaks manually breaks_adj = list( age.in.years=c(26, 35, 40), other.debtors.or.guarantors=c("none", "co-applicant%,%guarantor")) bins_adj = woebin(dt_f, y="creditability", breaks_list=breaks_adj) # converting train and test into woe values dt_woe_list = lapply(dt_list, function(x) woebin_ply(x, bins_adj)) # glm / selecting variables ------ m1 = glm( creditability ~ ., family = binomial(), data = dt_woe_list$train) # vif(m1, merge_coef = TRUE) # summary(m1) # Select a formula-based model by AIC (or by LASSO for large dataset) m_step = step(m1, direction="both", trace = FALSE) m2 = eval(m_step$call) # vif(m2, merge_coef = TRUE) # summary(m2) # performance ks & roc ------ ## predicted proability pred_list = lapply(dt_woe_list, function(x) predict(m2, x, type='response')) ## Adjusting for oversampling (support.sas.com/kb/22/601.html) # card_prob_adj = scorecard2(bins_adj, dt=dt_list$train, y='creditability', # x=sub('_woe$','',names(coef(m2))[-1]), badprob_pop=0.03, return_prob=TRUE) ## performance perf = perf_eva(pred = pred_list, label = label_list) # perf_adj = perf_eva(pred = card_prob_adj$prob, label = label_list$train) # score ------ ## scorecard card = scorecard(bins_adj, m2) ## credit score score_list = lapply(dt_list, function(x) scorecard_ply(x, card)) ## psi perf_psi(score = score_list, label = label_list)
