Add boxplot and dotplot visual tests

Author: wch

visual_test/boxplot.r

@@ -0,0 +1,7 @@
+vcontext("boxplot")
+
+ggplot(mtcars, aes(x = factor(cyl), y = drat, colour = factor(cyl))) +
+    geom_boxplot(outlier.size = 5)
+save_vtest("outlier colours")
+
+end_vcontext()

visual_test/dotplot.r

@@ -132,4 +132,15 @@ ggplot(dat2, aes(y, fill = g)) +
   facet_grid(x ~ .)
 save_vtest("facets, 3 groups, histodot, stackgroups")
 
+# Missing values
+dat2 <- dat
+dat2$x[c(1, 10)] <- NA
+
+ggplot(dat2, aes(x)) + geom_dotplot(binwidth = .4)
+save_vtest("2 NA values, dot-density binning, binwidth = .4")
+
+ggplot(dat2, aes(0, x)) +
+  geom_dotplot(binwidth = .4, binaxis = "y", stackdir = "center")
+save_vtest("2 NA values, bin along y, stack center")
+
 end_vcontext()