是否可以for for在R中循環“ sapply”？

Question

我想知道為什么我的對象CI無法在以下函數中正確返回for()循環的完整輸出（11對答案）？ 相反， CI返回11個單號。

N = 30 ; df = 118 ; d = 1

f <- function (ncp, alpha, q, df) {
 abs(suppressWarnings(pt(q = d*sqrt(N), df = df, ncp, lower.tail = FALSE)) - 
   alpha)
      }

 a = mapply(c, as.list(20:30), as.list(-20:-30), SIMPLIFY = FALSE) # a list of paired values

 CI <- numeric(length(a))

 for(i in 1:length(a)){

CI[i] = sapply(c(0.025, 0.975),
         function(x) optimize(f, interval = a[[i]], alpha = x, q = d*sqrt(N), df = df, tol = 1e-10)[[1]])

    }  

CI # just returns one paired of the 11 paired answers expected!

Answer 1

怎么樣：

N = 30 ; df = 118 ; d = 1

f <- function (ncp, alpha, q, df) {
  abs(suppressWarnings(pt(q = d*sqrt(N), df = df, ncp, lower.tail = FALSE)) - 
        alpha)
}

a = mapply(c, as.list(20:30), as.list(-20:-30), SIMPLIFY = FALSE) # a list of paired values

CI <- matrix(NA, 11,2)

for(i in 1:length(a)){

  CI[i,] = sapply(c(0.025, 0.975),
              function(x) optimize(f, interval = a[[i]], alpha = x, q = d*sqrt(N), df = df, tol = 1e-10)[[1]])

}  

CI