minor edits to thickness article

vignettes/thickness.Rmd

@@ -53,12 +53,12 @@ For example:
 
 ```{r intro}
 df = data.frame(
-  h = c(0,1,1,0, 0,2,2,0, 0,4/3,4/3,0, 0,1,1,0,     0,1.25,1.25,0, 0,.5,.5,0),
-  x = c(0,1,4,5, 4,5,6,7, 6,7,9,10,    11,12,15,16, 1,2,4.2,5.2,   4,5,12,13),
-  y =     rep(c("a", "b", "a", "a", "b", "a"), each = 4),
+  h = c(0,1,1,0, 0,2,2,0, 0,4/3,4/3,0,  0,1,1,0,     0,1.25,1.25,0, 0,.5,.5,0),
+  x = c(0,1,4,5, 4,5,6,7, 6,7,9,10,     11,12,15,16, 1,2,4.2,5.2,   4,5,12,13),
+  y     = rep(c("a", "b", "a", "a", "b", "a"), each = 4),
   group = rep(c("c", "c", "d", "d", "c", "c"), each = 4),
   panel = rep(c("e", "e", "e", "e", "f", "f"), each = 4),
-  name  = rep(c(1,2,"3a","3b",4,5), each = 4)
+  name  = rep(c( 1,   2, "3a","3b",  4,   5 ), each = 4)
 )
 
 df_group = df %>%
@@ -263,15 +263,23 @@ prior_post_plot = df_prior_post %>%
   scale_y_continuous(breaks = NULL) +
   theme(panel.background = element_rect(color = "gray70", fill = NA))
 
-prior_post_plot
+prior_post_plot +
+  labs(
+    title = "two different slab geometries",
+    subtitle = "thickness scales are not shared across geometries by default"
+  )
 ```
 
 Notice how the two geometries have different `thickness` scales. If we add `scale_thickness_shared()`
 to the plot, they will be given the same scale:
 
 ```{r prior_post_shared}
 prior_post_plot +
-  scale_thickness_shared()
+  scale_thickness_shared() +
+  labs(
+    title = "two different slab geometries",
+    subtitle = "using scale_thickness_shared() to share thickness scale across geometries"
+  )
 ```
 
 `scaled_thickness_shared()` works by scaling values and then tagging them with
@@ -429,7 +437,11 @@ data.frame(
   y = letters[1:10]
 ) %>%
   ggplot(aes(xdist = d, y = y)) +
-  stat_slab(height = 3, color = "gray25")
+  stat_slab(height = 3, color = "gray25") +
+  labs(
+    title = "geom_slab()",
+    subtitle = "using height > 1 to create ridgeline plots"
+  )
 ```
 
 ```{r reset_options, include=FALSE}