r - 使用长数据格式更改 ggplot2 图中的一种线型

Question

我有融化形式的数据

b <- data.table(q = seq(5), 
                A = rnorm(5, mean=1, sd=1), 
                B = rnorm(5, mean=1.5, sd=1), 
                C = rnorm(5, mean=2, sd=1))
longb <- melt.data.table(b, id.vars = 'q', measure.vars = c(names(b)[-1]))

绘制三条线必须做的：

ggplot(data = longb, aes(x = q, y = value, colour = variable)) +
  geom_line()

如果可以将系列之一（例如 C）从线更改为虚线图（例如geom_point()），我会徘徊吗？

标签： rggplot2

Answer 1

像这样的东西？

ggplot(data = longb, aes(x = q, y = value, colour = variable)) +
  geom_line(aes(linetype = (variable == "C"))) +
  guides(linetype = "none")

或更好：

ggplot(data = longb, aes(x = q, y = value, colour = variable)) +
  geom_line(aes(linetype = variable)) +
  scale_linetype_manual(values = c(1,1,3))

还是好？：

ggplot(data = longb[variable != "C"], aes(x = q, y = value, colour = variable)) +
  geom_line() +
  geom_point(data = longb[variable == "C"], aes(x = q, y = value))