如何在 geom_smooth()来自 ggplot2 包中为多重非线性回归分配不同的初始值？

如何解决如何在 geom_smooth()来自 ggplot2 包中为多重非线性回归分配不同的初始值？

我有 2 个数据集，一个用于 A 组，另一个用于 B 组。我想将数据直观地拟合到 y=1-exp(-kx) 模型中。为此，我使用了 ggplot2 包和 geom_smooth() 函数。在 geom_smooth() 函数的参数中，必须指明非线性拟合的初始值。由于我有 2 组数据，我想为每组分配不同的初始值。在这种情况下，对于 A 组，k 的初始值将是 0.45，而对于 B 组，它将是 0.015。但是，我不知道该怎么做。有人可以帮我吗？

library(ggplot2)


Group <- c("A","B")
x <- 0:10
y <- c(0,0.4,0.6,0.8,0.9,0.95,0.97,0.98,0.99,1,0.01,0.02,0.03,0.04,0.05,0.06,0.07,0.08,0.09,0.1)
start_values <- c(0.45,0.015)

df <- expand.grid(x = x,Group = Group)

df$y <- y

ggplot(data = df,aes(x = x,y = y)) +
  geom_point(aes(shape = Group,color = Group)) +
  geom_smooth(aes(color = Group),formula = y ~ 1-exp(-k*x),method = "nls",method.args = list(k = start_values),se = FALSE)

解决方法

据我所知，您无法使用 geom_smooth 轻松地为每个组传递不同的参数。一种选择是为每个组添加单独的图层

ggplot(data = df,aes(x = x,y = y)) +
  geom_point(aes(shape = Group,color = Group)) +
  geom_smooth(aes(color = Group),formula = y ~ 1-exp(-k*x),method = "nls",method.args = list(start = c(k=start_values[1])),se = FALSE,data = function(x) subset(x,Group=="A")) + 
  geom_smooth(aes(color = Group),method.args = list(start = c(k=start_values[2])),Group=="B"))

and this is my URLs 您也可以使用 mapply 为您创建它们，而不是为每个组手动添加图层

ggplot(data = df,color = Group)) +
  mapply(function(start,group) {
    geom_smooth(aes(color = Group),method.args = list(start = c(k=start)),Group==group))  
  },start_values,c("A","B"))