如何使用 ggplot 连接包含 NA 的观测值进行分面？

Question

只是为了使用 ggplot 和 facet 选项连接包含 NA 的观察结果

df <- data.frame(
    time = 1:5,
    y1 = c(4, 2, 3, 1, NA),
    y2 = c(4, 5, NA, 6, 10),
    y3 = c(8, 7, NA, 4, 5)
  )

  library(ggplot2)
  ggplot(df, aes(x=time, y=y2)) + geom_line() # no connection between observations

  ggplot(na.omit(df), aes(x=time, y=y2)) + geom_line() # a way to connect is to omit NAs but this works only when one variable 

  library(tidyr)
  df2 <- df %>% gather(key = "var", value = "values", 2:4)  # gather values from variables

  ggplot(df2, aes(x=time, y=values, colour = var)) + geom_line()+
  facet_wrap(~ var) # no connection between observations ==> issue !

有什么想法吗？

Answer 1

在使用gather函数时可以设置na.rm = TRUE去掉NA值，然后绘制数据。

library(tidyr)
df2 <- df %>% gather(key = "var", value = "values", 2:4, na.rm = TRUE)

ggplot(df2, aes(x = time, y = values, colour = var)) + 
  geom_line() +
  facet_wrap(~var)

如何使用 ggplot 连接包含 NA 的观测值进行分面？

How to connect observations containing NAs using ggplot for facetting?

r

ggplot2

facet-wrap

facet-grid