Alpha aesthetic shows arrow's skeleton instead of plain shape - how to prevent it?

Question

I\'m aiming at building a bar plot with arrows at the end of bars. I went for geom_segment with arrow defined. I want to map one column onto transp

Answer 1

You could use geom_gene_arrow from library(gggenes)

data.frame(y=c(10, 20, 30), n=c(300, 100, 200), transparency=c(10, 2, 4)) %>% 
  ggplot() + 
  geom_gene_arrow(aes(xmin = 0, xmax = n, y = y, alpha = transparency), 
                  arrowhead_height = unit(6, "mm"), fill='red') +
  scale_y_continuous(limits = c(5, 35))