为什么重命名的函数不像 R 中的原始函数那样工作

Question

我正在使用 match.call 将名为 factanal 的 BASE R 函数重命名为 efa。但我想知道为什么只有在使用参数公式x、efa 时会引发错误：object 'n.obs' not found 但factanal 工作正常？

注意：将data.frame 用于x 时，efa 工作正常。

efa <- function(x, factors, data = NULL, covmat = NULL, n.obs = NA,
            subset, na.action, start = NULL, center = FALSE,
            scores = c("none", "regression", "Bartlett"),
            rotation = "varimax", control = NULL, ...)
 {

 fit <- factanal(x, factors, data = data, covmat, n.obs = n.obs,
              subset, na.action, start = start,
              scores = scores,
              rotation = rotation, control = control, ...)

 fit$call <- match.call(expand.dots = FALSE)

 return(fit)
}

# Example of use:

v1 <- c(1,1,1,1,1,1,1,1,1,1,3,3,3,3,3,4,5,6)
v2 <- c(1,2,1,1,1,1,2,1,2,1,3,4,3,3,3,4,6,5)
v3 <- c(3,3,3,3,3,1,1,1,1,1,1,1,1,1,1,5,4,6)

factanal(~v1+v2+v3, factors = 1, data = data.frame(v1, v2, v3)) # Works fine
     efa(~v1+v2+v3, factors = 1, data = data.frame(v1, v2, v3)) # Error: object 'n.obs' not found

     efa(data.frame(v1, v2, v3), factors = 1) # Works fine

Answer 1

我认为更常见的方法是先捕获调用，包装任何参数，然后评估它。像这样的

efa <- function(x, factors, data = NULL, covmat = NULL, n.obs = NA,
                subset, na.action, start = NULL, center = FALSE,
                scores = c("none", "regression", "Bartlett"),
                rotation = "varimax", control = NULL, ...)
{

  cc <- match.call(expand.dots = FALSE)
  cc[[1]] <- quote(factanal)
  fit <- eval.parent(cc)
  fit$call <- match.call(expand.dots = FALSE)

  return(fit)
}

我们可以测试

efa(~v1+v2+v3, factors = 1, data = data.frame(v1, v2, v3))
# Call:
# efa(x = ~v1 + v2 + v3, factors = 1, data = data.frame(v1, v2,     v3))
# 
# Uniquenesses:
#    v1    v2    v3 
# 0.005 0.114 0.739 
# 
# Loadings:
#    Factor1
# v1 0.998  
# v2 0.941  
# v3 0.511  
# 
#                Factor1
# SS loadings      2.143
# Proportion Var   0.714
# 
# The degrees of freedom for the model is 0 and the fit was 0.0609 

否则此函数无法正常工作的原因是，当您将值传递给n.obs 时，它假定这是您的 data.frame 中包含您希望使用的值的变量的名称，它确实如此不要假设这是您当前环境中的变量。