在 R 中将数字 1000 格式化为 1k，将 1000000 格式化为 1m 等

Question

我需要像这样使用缩写来显示数字

1 shows as 1
999 shows as 999
1000 shows as 1K
999000 shows as 999K
1000000 shows as 1M
1500000 shows as 1.5M
1000000000 shows as 1G
etc...

我在 Whosebug 上看到了其他语言的问题（Javascript 至少三次）：

Format a javascript number with a Metric Prefix like 1.5K, 1M, 1G, etc

Format a number as 2.5K if a thousand or more, otherwise 900

How to format numbers similar to Stack Overflow reputation format

1000000 to 1M and 1000 to 1K in oracle query

1000 to 1k, 1000000 to 1m etc. number abbreviation

...但是我找不到 R 的任何内容。我是否遗漏了什么？

Answer 1

使用dplyr::case_when:

so_formatter <- function(x) {
  dplyr::case_when(
      x < 1e3 ~ as.character(x),
      x < 1e6 ~ paste0(as.character(x/1e3), "K"),
      x < 1e9 ~ paste0(as.character(x/1e6), "M"),
      TRUE ~ "To be implemented..."
  )
}

test <- c(1, 999, 1000, 999000, 1000000, 1500000, 1000000000, 100000000000)
so_formatter(test)


# [1] "1"                   
# [2] "999"                 
# [3] "1K"                  
# [4] "999K"                
# [5] "1M"                  
# [6] "1.5M"                
# [7] "To be implemented..."
# [8] "To be implemented..."

在 R 中将数字 1000 格式化为 1k，将 1000000 格式化为 1m 等

Format a number 1000 as 1k, 1000000 as 1m etc. in R

r

number-formatting