在R图中绘制平均值

Question

我想在我的散点图中为窗口添加一个值的平均值。我用ggplot2

创建了散点图

 p <- ggplot(mtcars, aes(wt, mpg)) 
p + geom_point()

这将给出散点图，但我想添加一个窗口的平均值（比如大小等于1）并将这个均值点绘制成一条线。另外，我想在每个点都有竖条来表示方差。

Mtcars是ggplot 2中提供的数据集标准

Answer 1

这使用新的dplyr库。

library(dplyr)
forLines <- mtcars %.% 
          group_by(cut(wt, breaks = 6)) %.%
          summarise(mean_mpg = mean(mpg), mean_wt = mean(wt))
p + 
  geom_point(size=5) +
  geom_boxplot(aes(group = cut(wt, breaks = 6))) +
  geom_line(data=forLines,aes(x=mean_wt,y=mean_mpg))

Answer 2

也许这就是你要找的东西：

library(ggplot2)

s <- seq(0, ceiling(max(mtcars$wt)), 1)
ind <- as.integer(cut(mtcars$wt, s))

myfun <- function(i) 
  c(y = mean(i), ymin = mean(i) - var(i), ymax = mean(i) + var(i))

ggplot(mtcars, aes(wt, mpg)) +
  geom_point() +
  stat_summary(fun.data = myfun, aes(group = ind, x = ind - .5), 
               colour = "red") +
  stat_summary(fun.y = mean, aes(x = ind - .5), geom = "line",
               colour = "red")

Answer 3

这是你想要的吗？

p <- ggplot(mtcars, aes(wt, mpg)) 
p + geom_point() + geom_smooth(aes(wt, mpg, group=1), method = "lm")