add legend subtitle

Author: wlangera

source/dataset_bias_cv.Rmd

@@ -1177,19 +1177,23 @@ p_improvement <- improvement_df %>%
     limits = c(-0.7, 0.7),
     trans = scales::pseudo_log_trans(sigma = 0.01),
     breaks = c(-0.6, -0.1, 0, 0.1, 0.6),
-    name = "Improvement"
+    name = paste0(
+      "Improvement<br>",
+      "<span style='font-size: 8pt'>",
+      "(transformed scale)</span>"
+    )
   ) +
   scale_x_discrete(label = function(x) stringr::str_trunc(x, 20)) +
   scale_y_discrete(label = function(x) stringr::str_trunc(x, 40)) +
   facet_wrap(~rarity, scales = "free_x") +
   labs(
     x = "",
-    y = "Dataset omitted",
-    fill = "Improvement"
+    y = "Dataset omitted"
   ) +
   theme_bw(base_size = 12) +
   theme(axis.text.x  = element_blank(),
-        legend.position = c(0.83, 0.28))
+        legend.position = c(0.83, 0.28),
+        legend.title = ggtext::element_markdown())
 p_improvement
 ```