如何更改ggplot中geom\u line()中线条的颜色顺序

你需要转身 GeoName 并将其级别设置为正确的顺序。例如,我们可以按2009年的值着色:

library(ggplot2)
library(dplyr)

df <- data_frame(GeoName = rep(LETTERS, 3)) %>% 
  arrange(GeoName) %>% 
  mutate(year = rep(c(2009, 2010, 2011), 26),
         percent_change = sample(seq(-3, 3, .1), 78, T))

# here is the change:
df$GeoName <- factor(
                df$GeoName,
                levels = (filter(df, year == 2009) %>%
                  arrange(desc(percent_change)))$GeoName)

#create my color ramp function
YlGnBu <- colorRampPalette(RColorBrewer::brewer.pal(9, 'YlGnBu'))


df %>% 
  ggplot(aes(year,
             percent_change,
             group = GeoName,
             color = GeoName))+
  geom_point(show.legend = F)+
  geom_line(show.legend = F)+
  scale_color_manual(values = YlGnBu(n_distinct(df$GeoName)))+ # color function 
  scale_x_continuous(breaks = c(2009, 2010, 2011))+              # from above
  theme(panel.background = element_blank(),
        panel.grid = element_blank(),
        axis.line = element_line(color = 'black')) 

因为这些线纵横交错,它们只能在一年内按自然顺序排列。你需要选择一个最适合你想要讲述的故事的。