r - 将值匹配到 R 中另一个列表中最近的较大值

Question

有several questions关于如何从列表中找到最接近给定数字的数字。这些答案主要涉及 which 或 which.min 是双向的，因此它们从列表中返回最接近给定数字的数字，而不管它是否数字大于或小于给定数字。

我想强制返回的数字大于给定的数字，除非给定的数字本身出现在列表中。这个功能可以，但是有没有更简单的方法呢？

viable_numbers <- c(15, Inf, 5, 10, 5)

picker <- function(x, viable_numbers) {
  if (x %in% viable_numbers) {
    return(x)
    
  } else {
    viable_numbers <- sort(unique(viable_numbers))
    return(viable_numbers[findInterval(x, viable_numbers) + 1])
  }
}
    
picker(x = 1, viable_numbers = viable_numbers)
[1] 5 # works
picker(x = 5, viable_numbers = viable_numbers)
[1] 5 # works
picker(x = 6, viable_numbers = viable_numbers)
[1] 10 # also works
picker(x = 20, viable_numbers = viable_numbers)
[1] Inf # still working

我更喜欢 base 解决方案，但也对 tidyverse 答案持开放态度。

Answer 1

您可以取等于或大于 x 的可行数子集的最小值:

picker <-  function(x, viable_numbers) {
  min(viable_numbers[viable_numbers >= x])
}

picker(x = 1, viable_numbers = viable_numbers)
[1] 5
picker(x = 5, viable_numbers = viable_numbers)
[1] 5 
picker(x = 6, viable_numbers = viable_numbers)
[1] 10 
picker(x = 20, viable_numbers = viable_numbers)
[1] Inf