Restrict stat_ellipse to certain data points

Question

I have a dataset with four categories of vowel, akin to the following:

speaker   vowel_category  f1    f2
1          a              x     x
1          b              x     x
1          c              x     x
1          d              x     x
2          a              x     x
2          b              x     x...

This geom_point code plots them all one one graph with stat_ellipse and is 90% what I need:

ggplot(data = topicsubset_ikf, aes(x = F2, y = F1, shape = CATEGORY)) +
  geom_point() +
  scale_y_reverse() +
  scale_x_reverse() +
  xlab("F2") +
  ylab("F1") + 
  labs(title = "All speakers with KIT and FLEECE tokens") +
  coord_cartesian(xlim = c(1.9, 1.1), ylim = c(0.3, 1.5)) +
  facet_wrap(~ SPEAKER) +
  scale_color_manual(values = c("#000000", "#FF8F00", "#000000", "#A200FF")) +
  stat_ellipse(geom = "polygon", alpha = 1 / 2, aes(fill = CATEGORY))

However, it would be ideal if I could draw ellipses round just two of the four categories (say, a and b), rather than all 4, so I can look at the spread of c & d relative to a and b. I haven't been able to find a way so far - I've tried combining multiple datasets on one graph to no avail. Any suggestions?

`stat_ellipse(data = subset(topicsubset_ikf, CATEGORY %in% ....)` Try subsetting the data fed to the geom. — missuse, Oct 24 '17 at 10:45

score 1 · Answer 1 · answered Oct 28 '20 at 11:31

1

I had the same problem, I found that now you can just specify the group in stat_ellipse like this:

stat_ellipse(geom = "polygon", alpha = 1 / 2, aes(fill = CATEGORY, group = CATEGORY))

answered Oct 28 '20 at 11:31

Alejandro Plazas

11
1

Restrict stat_ellipse to certain data points

1 Answers1