#22 Add check for character variables in explainer dataset

R/modelDown.R

@@ -152,6 +152,12 @@ validateExplainers <- function(explainers){
     if(class(explainer) != "explainer"){
       stop("All explainers must be of class 'explainer' (generated by explain() from DALEX package)")
     }
+
+    if(any(sapply(explainer$data, class) == "character")){
+      print("Found character variables:")
+      print(names(explainer$data)[sapply(explainer$data, class) == "character"])
+      stop("Character variables are not supported! Please remove them or convert to factors")
+    }
   }
 
   # Check if explainers have the same columns

tests/testthat/test_modelDown.R

@@ -36,3 +36,18 @@ test_that("Default arguments", {
   })
 })
 
+
+test_that("Validation for character variable in explainer dataset", {
+  expect_error({
+    require("DALEX")
+
+    titanic_char <- titanic
+    titanic_char$country_character <- as.character(titanic$country)
+
+    titanic_glm_model <- glm(survived == "yes" ~ ., titanic_char, family = "binomial")
+
+    explainer_glm <-
+      explain(titanic_glm_model, data = titanic_char, y = titanic_char$survived)
+    modelDown::modelDown(explainer_glm)
+  })
+})