r - 如何从 biglm 对象中提取公式？

Question

如何从biglm对象中提取公式？我已经尝试过函数 as.formula()，但它没有返回我期望的结果。示例:

m1 = lm(Fertility ~ Agriculture + Examination + Education + Catholic + Infant.Mortality, data=swiss)
as.formula(m1) # returns only the formula expression (that's what I want!)
# returns: Fertility ~ Agriculture + Examination + Education + Catholic + Infant.Mortality

library(biglm)
m2 = biglm(Fertility ~ Agriculture + Examination + Education + Catholic + Infant.Mortality, data=swiss)
as.formula(m2) # returns many things, but I want only the formula expression

Answer 1

您可以使用术语和公式:

formula(terms(m2))

Fertility ~ Agriculture + Examination + Education + Catholic + 
    Infant.Mortality