ggplot的置信区间

Question

如果要在同一图上绘制两组数据，是否有任何方法可以仅获取其中一个数据集而不获取另一个数据集的置信区间？ 例如，回归仅显示对数据组A有意义，而对B则不显着，但是您仍然希望在同一图中直观地描绘A和B的数据，而置信区间仅在重要组A周围。

Answer 1

您可以有选择地选择要传递给回归绘图仪的数据。

考虑以下示例：

set.seed(10)

#Make sample data
df <- data.frame(
  group=rep(c("A","B"), each=10),
  X = rep(1:10, 2))
df$Y <- 2*df$X + runif(20, -20, 20)  #Create y values with lots of noise

#Reduce the noise for group A
df[df$group == "A", "Y"] <- 2*df[df$group == "A", "X"] + rnorm(10)

#Compare regression p-values
coef(summary(lm(Y ~ X, data=df[df$group == "A", ])))[, 4] #p < 0.05 for group A
# (Intercept)            X 
#1.577943e-01 5.411004e-09 

coef(summary(lm(Y ~ X, data=df[df$group == "B", ])))[, 4] #p > 0.05 for group B
#(Intercept)           X 
#  0.7338232   0.1309030

#Graph all points, coloring by group.  Add a regression line for group A only.
ggplot(df, aes(x=X, y=Y, colour= group)) + theme_bw() + 
   geom_point(size=2.5) + 
   geom_smooth(data = df[df$group == "A",], method="lm")