R中具有因子變量的線圖

Question

如何根據因子變量在兩個觀測值之間繪制R畫線？

我有兩個“時間”點，分別是早期和晚期，按類別分類

plotdata <- structure(list(
               x = structure(1:2, .Label = c("early", "late"), class = "factor"), 
               y = 1:2
               ),
            .Names = c("x", "y"), row.names = c(NA, -2L), class = "data.frame"
)

我只得到一種條形圖：

plot(plotdata)

我也嘗試將變量編碼為0和1，但隨后得到一個連續軸。

Answer 1

假設您的數據是

d <- structure(list(x = structure(1:2, .Label = c("early", "late"), class = "factor"), 
    y = 1:2), .Names = c("x", "y"), row.names = c(NA, -2L), class = "data.frame")
d
#       x y
#   early 1
#    late 2

帶底腳R

plot(as.numeric(d$x), d$y, type = "l", xaxt = "n")
axis(1, labels = as.character(d$x), at = as.numeric(d$x))

使用ggplot2

library(ggplot2)
ggplot(d, aes(x = x, y = y)) + geom_line(aes(group = 1))