Getting transition_states, geom_label_repel and enter

I'm drawing a scatterplot where I'd like to highlight different observations as time passes. Sometimes, these observations are close together, so I'm using geom_label_repel to do so. I'd also like to use enter_fade and exit_fade in order to make smoother the transition between phases of the animation.

I see from elsewhere (eg


set.seed(24601)
library(stringi)
library(tidyverse)
library(gganimate)
library(ggrepel)

x <- 
  rnorm(100, 0, 1)
y <- 
  rnorm(100, 0, 1)
names <- 
  stri_rand_strings(100,
                    5)
categories <- 
  rep(c("a", "b", "c", "d", "e"), 5)

ggplot(data.frame(x, y, names, categories))   
  aes(x = x,
      y = y)   
  geom_point(data = . %>% 
               select(- categories))   
  geom_label_repel(aes(label = names,
                       group = categories),
                   seed = 24601)   
  transition_states(categories)    
  enter_fade()   
  exit_fade()

CodePudding user response：

What's happening is that during the transitions, the location and number of labels within the plot are not consistent. This causes geom_label_repel() to force labels away from each other. You can set force = 0 so that your labels are not repelled from each other (default force is 1), but instead only repelled from points.

ggplot(data.frame(x, y, names, categories))   
  aes(x = x,
      y = y)   
  geom_point(data = . %>% 
               select(- categories))   
  geom_label_repel(aes(label = names,
                       group = categories),
                   seed = 24601,
                   force = 0)   
  transition_states(categories)    
  enter_fade()   
  exit_fade()

As you can see, you will have some labels overlap. However, if important, you could play with lower values of force (e.g. force = 0.1) so the labels only shift slightly but overlap less.

Although most are stable, I am getting a couple of random labels popping up and not transitioning, will investigate.