用R中的ggplot2中的线连接来自两个数据集的点

Question

I want to connect datapoints from two datasets with a vertical line. The points that should be connected vertically have the same identifier (V), but I was hoping to keep the datasets separate.

Here is my figure so far:

d1 <- data.frame (V = c("A", "B", "C", "D", "E",  "F", "G", "H"), 
                  O = c(9,2.5,7,8,7,6,7,7.5), 
                  S = c(6,5,3,5,3,4,5,6))

d2 <- data.frame (V = c("A", "B", "C", "D"), 
              O = c(10,3,7.5,8.2), 
              S = c(6,5,3,5))

scaleFUN <- function(x) sprintf("%.0f", x)
p<-ggplot(data=d1, aes(x=S, y=O), group=factor(V), shape=V) +
 geom_point(size = 5, aes(fill=V),pch=21, alpha = 0.35)+
 theme_bw()+
geom_point(data = d2, size=5, aes(fill=V), pch=22,colour="black")+
theme(legend.title=element_blank())+
xlab(expression(italic("S"))) + theme(text = element_text(size=25))+
ylab(expression(italic("O")))+ theme(text = element_text(size=25))+
theme(panel.grid.major = element_blank(), panel.grid.minor = element_blank())+
theme(axis.text.y=element_text(angle=90, hjust=1))+
theme(legend.position="none") # remove legend

print(p)

So the final figure would look something like this: Can I do this with geom_line() without combining datasets (so the other formatting can be separate for each dataset)?

Answer 1

As bouncyball pointed out, you can use a separate data set ( merge d from d1 and d2 ) with geom_segment .

See the following:

ggplot(data = d1, aes(x = S, y = O), group = factor(V), shape = V) +
  geom_point(size = 5, aes(fill = V), pch = 21, alpha = 0.35) +
  geom_point(data = d2, size = 5, aes(fill = V), pch = 22, colour = "black") +
  geom_segment(data = merge(d1, d2, by = 'V'), 
               aes(x = S.x, xend = S.y, y = O.x, yend = O.y)) +
  guides(fill = FALSE)

Which yields:

You can add your themes also.