r - ggplot 更改由 x 轴值指定的线条颜色

Question

要重现的代码:

myDat <- data.frame(Event = rep(c("Arrival", "Departure"), 3),
                AtNode = c("StationA", "StationA", "Track", "Track", "StationB", "StationB"),
                Lane = c("Lane1", "Lane1", "Lane2", "Lane2", "Lane1", "Lane1"),
                atTime = c(10, 12, 18, 20, 34, 36),
                Type = c("Station", "Station", "Track", "Track", "Station", "Station"),
                Train = 1 )
ggplot(data =myDat, aes(x = atTime, y=factor(AtNode, levels = unique(paste(myDat[order(myDat$atTime),"AtNode"]))), group = Train, colour = Lane ))+
  geom_point(data = myDat)+
  geom_path(data = myDat[which(!grepl(pattern = "Track", myDat$Type)),])

现在我需要将两个绿色点(Y = “Track”)投影到橙色线上，并将投影点之间的线着色为与点相同的颜色。

预期结果:(没有分数(Y ="Track")

提前感谢每一个提示或技巧!

干杯

Answer 1

我认为您的输出不是展示您想要的内容的正确方式。您的 y 轴 上有 factors，这意味着它的范围在 1 到 3 之间。

因此，在 y 轴 值方面，在那里投影一条线没有任何意义。

对我来说，显示数据的正确方式是这样的

ggplot(data =myDat,
       aes(x = atTime, y=factor(AtNode, levels = unique(paste(myDat[order(myDat$atTime),"AtNode"]))), 
           group = AtNode, colour = Lane ))+
  geom_point()+
  geom_line() +
  labs(y = 'AtNode')

但是，按照你的要求，你可以做一些简单的三角函数来投影你的线段

x1 = 1 + tan(asin(2/sqrt(484)))*6 #y projection given x = 18
x2 = 1 + tan(asin(2/sqrt(484)))*8 #y projection given x = 20

foo = data.frame(x = c(18,20), y = c(x1, x2), Lane = "Lane2")

ggplot(data = myDat, aes(x = atTime, y=factor(AtNode, levels = unique(paste(myDat[order(myDat$atTime),"AtNode"]))), group = 1, colour = Lane ))+
  geom_path(data = myDat[which(!grepl(pattern = "Track", myDat$Type)),]) +
  geom_line(data = foo, aes(x = x, y = y, color = Lane), size = 1) +
  scale_y_discrete(drop = FALSE)