分组group

library(dplR)
data(package = "dplR")
data(nm046)

nm046 %>% 
  mutate(year =as.double(rownames(.)), .before = 1) %>% 
  pivot_longer(cols = !year, names_to = "tree", values_to = "value") %>% 
  ggplot(aes(x = year, y = value, group = tree, color = tree))+
  geom_line()+
  theme_bw()

分面

nm046 %>% 
  mutate(year =as.double(rownames(.)) , .before = 1) %>% 
  pivot_longer(cols = !year, names_to = "tree", values_to = "value") %>% 
  ggplot(aes(x = year, y = value, group = tree, color = tree))+
  geom_line()+
  facet_wrap(~tree, ncol = 2)+
  theme_bw()