fix anova error (#427)

NEWS.md

@@ -7,6 +7,7 @@
 ### Bug Fixes
 
 - Previously if a secondary optimizer fails `mmrm` will fail. This is fixed now.
+- Previously character covariate variable will make `Anova` fail. This is fixed now.
 
 # mmrm 0.3.9
 

R/interop-car.R

@@ -40,7 +40,7 @@ h_get_contrast <- function(object, effect, type = c("II", "III", "2", "3"), tol
   assert_subset(effect, colnames(fcts))
   idx <- which(effect == colnames(fcts))
   cols <- which(asg == idx)
-  data <- component(object, "full_frame")
+  data <- model.frame(object)
   var_numeric <- vapply(data, is.numeric, FUN.VALUE = TRUE)
   coef_rows <- length(cols)
   l_mx <- matrix(0, nrow = coef_rows, ncol = length(asg))
@@ -64,7 +64,9 @@ h_get_contrast <- function(object, effect, type = c("II", "III", "2", "3"), tol
         },
         "3" = ,
         "III" = {
-          additional_levels <- vapply(data[additional_vars], function(x) nlevels(x), FUN.VALUE = 1L)
+          additional_levels <- vapply(data[additional_vars], function(x) {
+            if (is.factor(x)) nlevels(x) else length(unique(x))
+          }, FUN.VALUE = 1L)
           t_levels <- prod(additional_levels)
           l_mx[, cols] / t_levels
         }

tests/testthat/test-car.R

@@ -58,6 +58,24 @@ test_that("Anova works as expected", {
   )
 })
 
+## Anova with character covariates
+
+test_that("Anova works if covariate are character", {
+  skip_if_not_installed("car")
+  fev2 <- fev_data
+  fev2$ARMCD <- as.character(fev2$ARMCD)
+  fit <- mmrm(FEV1 ~ ARMCD * AVISIT + ar1(AVISIT | USUBJID), data = fev2)
+  fit2 <- mmrm(FEV1 ~ ARMCD * AVISIT + ar1(AVISIT | USUBJID), data = fev_data)
+  expect_identical(
+    Anova(fit, "III"),
+    Anova(fit2, "III")
+  )
+  expect_identical(
+    Anova(fit, "II"),
+    Anova(fit2, "II")
+  )
+})
+
 # Anova Integration Test ----
 
 test_that("Anova give similar results to SAS", {