是否有R函数使用单位前缀格式化数字

Question

是否有R函数(或任何包)允许使用标准单位前缀(Kilo,Mega等...)格式化数字(整数),所以

10 -> 10
100 -> 1K
0.01 - > 10m

等等......我可以自己做,但我宁愿不重新发明轮子.

Answer 1

require(sitools)
f2si(80000)
 [1] "80 k"
f2si(8E12)
 [1] "8 T"

它似乎非常简单,因为如果没有使用SI前缀,它会附加两个空格:

f2si(80)
[1] "80  "

该功能易于修改,包括舍入.我还修复了附加空格的问题.

f2si2<-function (number,rounding=F) 
{
    lut <- c(1e-24, 1e-21, 1e-18, 1e-15, 1e-12, 1e-09, 1e-06, 
        0.001, 1, 1000, 1e+06, 1e+09, 1e+12, 1e+15, 1e+18, 1e+21, 
        1e+24)
    pre <- c("y", "z", "a", "f", "p", "n", "u", "m", "", "k", 
        "M", "G", "T", "P", "E", "Z", "Y")
    ix <- findInterval(number, lut)
    if (lut[ix]!=1) {
        if (rounding==T) {
         sistring <- paste(round(number/lut[ix]), pre[ix])
        }
        else {
         sistring <- paste(number/lut[ix], pre[ix])
        } 
    }
    else {
        sistring <- as.character(number)
    }
    return(sistring)
}

f2si2(12345)
 [1] "12.345 k"
f2si2(12345,T)
 [1] "12 k"

Answer 2

我带着同样的问题来到这里.感谢罗兰的回答; 我在他的代码上进行了一些改动:

• 当舍入= FALSE时允许指定有效数字(默认为6就像'signif'内置函数一样)
• 不会抛出低于1e-24的值的错误
• 输出科学计数法(无单位)以获得高于1e27的值

希望这是有帮助的.

f2si<-function (number, rounding=F, digits=ifelse(rounding, NA, 6)) 
{
    lut <- c(1e-24, 1e-21, 1e-18, 1e-15, 1e-12, 1e-09, 1e-06, 
        0.001, 1, 1000, 1e+06, 1e+09, 1e+12, 1e+15, 1e+18, 1e+21, 
        1e+24, 1e+27)
    pre <- c("y", "z", "a", "f", "p", "n", "u", "m", "", "k", 
        "M", "G", "T", "P", "E", "Z", "Y", NA)
    ix <- findInterval(number, lut)
    if (ix>0 && ix<length(lut) && lut[ix]!=1) {
        if (rounding==T && !is.numeric(digits)) {
            sistring <- paste(round(number/lut[ix]), pre[ix])
        }
        else if (rounding == T || is.numeric(digits)) {
            sistring <- paste(signif(number/lut[ix], digits), pre[ix])
        }
        else {
            sistring <- paste(number/lut[ix], pre[ix])
        } 
    }
    else {
        sistring <- as.character(number)
    }
    return(sistring)
}

f2si(12345)
 [1] "12.345 k"
f2si(12345, T)
 [1] "12 k"
f2si(10^31)
 [1] "1e+31" # (previous version would output "1e+07 Y"
f2si(10^-25)
 [1] "1e-25" # (previous version would throw error)
f2si(123456789)
 [1] "123.457 M" # (previous version would output ""123.456789 M"
f2si(123456789, digits=4)
 [1] "123.5 M" # (note .456 is rounded up to .5)

从这段代码中,为常用的金融单位(K,MM,Bn,Tr)编写类似的函数也很容易.