R:在函数中包装多项式回归的问题

R: Problems of wrapping polynomial regression in a function

当我做多项式回归时,我试图将不同次数的多项式拟合到一个列表中,所以我将 glm 包装到一个函数中:

library(MASS)

myglm <- function(dop) {
    # dop: degree of polynomial
    glm(nox ~ poly(dis, degree = dop), data = Boston)
}

不过,我想可能存在一些与懒惰求值相关的问题。模型的度数是参数dop而不是具体的数字。

r$> myglm(2)

Call:  glm(formula = nox ~ poly(dis, degree = dop), data = Boston)

Coefficients:
             (Intercept)  poly(dis, degree = dop)1  poly(dis, degree = dop)2  
                  0.5547                   -2.0031                    0.8563  

Degrees of Freedom: 505 Total (i.e. Null);  503 Residual
Null Deviance:      6.781
Residual Deviance: 2.035        AIC: -1347

当我使用此模型进行交叉验证时,出现错误:

>>> cv.glm(Boston, myglm(2))
Error in poly(dis, degree = dop) : object 'dop' not found

那么我该如何解决这个问题呢?

Quosures, quasiquotation, and tidy evaluation 在这里很有用:

library(MASS)
library(boot)
library(rlang)

myglm <- function(dop) {
  eval_tidy(quo(glm(nox ~ poly(dis, degree = !! dop), data = Boston)))
}
cv.glm(Boston, myglm(2))