Sankey in rows

gistfile1.txt

library(tidyverse)
library(ggsankey)
library(gapminder)

df <- gapminder %>%
  group_by(continent, year) %>%
  summarise(gdp = (sum(pop * gdpPercap)/1e9) %>% round(0), .groups = "keep") %>%
  ungroup()

ggplot(df, aes(x = year,
                                         node = continent,
                                         fill = continent,
                                         value = gdp,
                                         shift = shift)) +
  geom_sankey_bump(data = df %>% mutate(shift = 0), space = 1500, type = "sankey", color = "transparent", smooth = 6) +
  geom_sankey_bump(data = df %>% mutate(shift = 70000), space = 1500, type = "sankey", color = "transparent", smooth = 6) +
  geom_sankey_bump(data = df %>% mutate(shift = 70000*2), space = 1500, type = "sankey", color = "transparent", smooth = 6) +
  geom_sankey_bump(data = df %>% mutate(shift = 0), space = 1500, type = "sankey", color = "transparent", smooth = 6) +
  scale_fill_viridis_d(option = "A", alpha = .8) +
  theme_sankey_bump(base_size = 16) +
  labs(x = NULL,
       y = "GDP ($ bn)",
       fill = NULL,
       color = NULL) +
  theme(legend.position = "bottom") +
  labs(title = "GDP development per continent")