Fix estimate_density plotting error with vector input and group_by

R/plot.estimate_density.R

@@ -11,6 +11,17 @@ data_plot.estimate_density <- function(
   if (!"Parameter" %in% names(dataplot)) {
     dataplot$Parameter <- "Distribution"
   }
+
+  # Handle case where Parameter column exists but is empty or malformed
+  if ("Parameter" %in% names(dataplot)) {
+    # Check for various problematic conditions
+    if (length(dataplot$Parameter) == 0 || 
+        all(is.na(dataplot$Parameter)) || 
+        all(dataplot$Parameter == "") ||
+        length(unique(dataplot$Parameter[!is.na(dataplot$Parameter)])) == 0) {
+      dataplot$Parameter <- rep("Distribution", nrow(dataplot))
+    }
+  }
 
   # add component and effects columns
   if (!is.null(data)) {
@@ -23,11 +34,20 @@ data_plot.estimate_density <- function(
 
   dataplot <- .fix_facet_names(dataplot)
 
-  dataplot$Parameter <- factor(dataplot$Parameter)
-  dataplot$Parameter <- factor(
-    dataplot$Parameter,
-    levels = rev(levels(dataplot$Parameter))
-  )
+  # Safely convert Parameter to factor, ensuring it has valid data
+  if ("Parameter" %in% names(dataplot) && 
+      length(dataplot$Parameter) > 0 &&
+      length(dataplot$Parameter) == nrow(dataplot) &&
+      !all(is.na(dataplot$Parameter))) {
+    dataplot$Parameter <- factor(dataplot$Parameter)
+    dataplot$Parameter <- factor(
+      dataplot$Parameter,
+      levels = rev(levels(dataplot$Parameter))
+    )
+  } else {
+    # If Parameter column is still problematic, set a default with correct length
+    dataplot$Parameter <- factor(rep("Distribution", nrow(dataplot)))
+  }
 
   # summary
   split_columns <- intersect(
@@ -250,6 +270,12 @@ plot.see_estimate_density <- function(
       p <- p + facet_wrap(~Component, scales = "free", ncol = n_columns)
     }
   }
+
+  # Handle Group column for grouped data (e.g., from group_by in estimate_density)
+  # Only add facets if not already faceting by other variables and if we have groups
+  if ("Group" %in% names(x) && is.null(n_columns)) {
+    p <- p + facet_wrap(~Group, scales = "free")
+  }
 
   p
 }

tests/testthat/test-plot.estimate_density.R

@@ -9,6 +9,18 @@ test_that("`plot.see_estimate_density()` works", {
 })
 
 
+test_that("`plot.see_estimate_density()` works with group_by and vector input", {
+  skip_if_not_installed("bayestestR")
+
+  # Test case that was failing: vector input with group_by
+  df <- bayestestR::estimate_density(iris[c("Species", "Petal.Width")], group_by = "Species")
+
+  # This should not error
+  expect_no_error(p <- plot(df))
+  expect_s3_class(p, "gg")
+})
+
+
 test_that("`plot.see_estimate_density()`, adding prior layers works", {
   skip_if_not_installed("curl")
   skip_if_offline()