example sankey diagram

sankey-ex.R

library(tibble)
library(dplyr)
library(tidyr)
library(ggplot2)
library(ggsankey)

df <-
  tibble(
    id = c(
      letters[1:13],
      letters[c(1:3, 5, 7, 9, 11:12)],
      letters[c(1:2, 5, 7, 9, 11)]
    ),
    node = c(
      rep('Multiple', 4), rep('Single - Associational', 2), rep('Single - Community', 2), rep('Single - Occupational', 2), rep('State', 3),
      rep('Multiple', 3), rep('Single - Associational', 1), rep('Single - Community', 1), rep('Single - Occupational', 1), rep('State', 2),
      rep('Multiple', 2), rep('Single - Associational', 1), rep('Single - Community', 1), rep('Single - Occupational', 1), rep('State', 1)
    ),
    year = c(
      rep(2002, 13),
      rep(2010, 8),
      rep(2020, 6)
    )
  )

# i think your data looks like this?
df_w_nas <- df %>% 
  expand(id, year) %>% 
  left_join(df) %>% 
  arrange(id, year)

network_w_nas <- df_w_nas %>% 
  arrange(id, year) %>% 
  group_by(id) %>% 
  mutate(
    next_year = lead(year)
  ) %>% 
  ungroup()

network_w_nas %>% 
  ggplot() +
  aes(x = year, next_x = next_year, node = node, next_node = node) +
  geom_sankey(
    flow.alpha = .6,
    # node.color = 'gray30', # this is the issue, assuming you're using some of the code in the package README here: https://github.com/davidsjoberg/ggsankey/blob/main/README.Rmd#L313-L322
    aes(fill = node)
  ) +
  geom_sankey_label(
    aes(label = node),
    # color = 'white', 
    # fill = 'gray40',
    size = 3
  ) +
  scale_fill_viridis_d() +
  theme_sankey() +
  labs(x = NULL) +
  theme(
    legend.position = "none",
    plot.title = element_text(hjust = .5)
  )