r - 使用 ggplot 绘制曲线拟合

Question

如何使用 ggplot 绘制最佳拟合线的曲线？我最好的猜测是我需要以某种方式更改 stat_smooth 参数，但我不知道如何更改。我的目标类似于下图中的黑线。

vv<-structure(list(X = 16:19, school = structure(c(3L, 3L, 3L, 3L), .Label = c("UCB", "UCD", "UIUC"), class = "factor"), year = 2009:2012, mean = c(15.60965, 16.785, 16.77725, 15.91729), sd = c(6.483547,6.852999, 6.327013, 6.74991)), .Names = c("X", "school", "year", "mean", "sd"), row.names = 16:19, class = "data.frame")

ggplot(vv, aes(x = year, y = mean)) + 
  ggtitle("scores")+
  geom_point() +
  stat_smooth(method = "lm", col = "red")

Answer 1

您可以尝试更改公式:

ggplot(vv, aes(x = year, y = mean)) + 
  ggtitle("scores")+
  geom_point() +
  stat_smooth(method = "lm", formula = y ~ splines::bs(x, 3), col = "red")