格式化大貨幣或美元價值上百萬/十億

Question

我需要一個簡單的函數或包，將格式化：

1 6,000,000 
2 75,000,400 
3 743,450,000 
4 340,000 
5 4,300,000 

要：

1 6.0 M 
2 75.0 M 
3 743.5 M 
4 0.3 M 
5 4.3 M 

或以其他方式大值（千萬，上億）在桌面上打印更清晰。

Answer 1

如果你開始這個數字矢量x，

x <- c(6e+06, 75000400, 743450000, 340000, 4300000) 

你可以做到以下幾點。

paste(format(round(x/1e6, 1), trim = TRUE), "M") 
# [1] "6.0 M" "75.0 M" "743.5 M" "0.3 M" "4.3 M" 

如果你不關心尾隨零，只是刪除format()電話。

paste(round(x/1e6, 1), "M") 
# [1] "6 M"  "75 M" "743.5 M" "0.3 M" "4.3 M" 

另外，你可以指定與打印方法的S3級，並保持y作爲數字下方。這裏我使用paste0()來使結果更清晰。

print.million <- function(x, quote = FALSE, ...) { 
    x <- paste0(round(x/1e6, 1), "M") 
    NextMethod(x, quote = quote, ...) 
} 
## assign the 'million' class to 'x' 
class(x) <- "million" 
x 
# [1] 6M  75M 743.5M 0.3M 4.3M 
x[] 
# [1] 6000000 75000400 743450000 340000 4300000 

您也可以爲億萬和萬億做同樣的事情。有關如何將其放入數據框的信息，請參閱this answer，因爲您需要使用format()和as.data.frame()方法。

Answer 2

另一種選擇，從數字（而不是字符）開始，並且適用於數百萬和數十億（及以下）。您可以將更多參數傳遞給formatC以自定義輸出，並在需要時擴展到萬億。

m_b_format = function(x) { 
    b.index = x >= 1e9 
    m.index = x >= 1e5 & x < 1e9 

    output = formatC(x, format = "d", big.mark = ",") 
    output[b.index] = paste(formatC(x[b.index]/1e9, digits = 1, format = "f"), "B") 
    output[m.index] = paste(formatC(x[m.index]/1e6, digits = 1, format = "f"), "M") 
    return(output) 
} 

your_x = c(6e6, 75e6 + 400, 743450000, 340000, 43e6) 
> m_b_format(your_x) 
[1] "6.0 M" "75.0 M" "743.5 M" "0.3 M" "43.0 M" 

big_x = c(123, 500, 999, 1050, 9000, 49000, 105400, 998000, 
      1.5e6, 2e7, 313402182, 453123634432) 
> m_b_format(big_x) 
[1] "123"  "500"  "999" "1,050" "9,000" "49,000" 
[7] "0.1 M" "1.0 M" "1.5 M" "20.0 M" "313.4 M" "453.1 B" 

Answer 3

這使用findInterval來定義後綴並確定分母。可在任一方向很容易地擴展，如果一個想去低於1.0或高於1萬億：

comprss <- function(tx) { 
     div <- findInterval(as.numeric(gsub("\\,", "", tx)), 
          c(1, 1e3, 1e6, 1e9, 1e12)) 
     paste(round(as.numeric(gsub("\\,","",tx))/10^(3*(div-1)), 2), 
      c("","K","M","B","T")[div])} 

您不必刪除as.numeric或GSUB如果輸入的是數字。毫無疑問，這是多餘的，但會成功。這與Grgor的示例的結果：（這實際上是一個因子可變）

> comprss (big_x) 
[1] "123 "  "500 "  "999 "  "1.05 K" "9 K"  
[6] "49 K"  "105.4 K" "998 K" "1.5 M" "20 M"  
[11] "313.4 M" "453.12 B" 

並與原來的輸入

comprss (dat$V2) 
[1] "6 M"  "75 M"  "743.45 M" "340 K" "4.3 M" 

當然，這些的並且可以在不使用一個顯式的報價被打印print命令和引號= FALSE或使用cat。

Answer 4

借用其他答案並添加它們的主要目的是爲ggplot2軸生成漂亮的標籤。是的，只有正值（負值將保持不變），因爲通常我只希望這些後綴用於正數量。易於擴展到負數。

# Format numbers with suffixes K, M, B, T and optional rounding. Vectorized 
# Main purpose: pretty formatting axes for plots produced by ggplot2 
# 
# Usage in ggplot2: scale_x_continuous(labels = suffix_formatter) 

suffix_formatter <- function(x, digits = NULL) 
{ 
    intl <- c(1e3, 1e6, 1e9, 1e12); 
    suffixes <- c('K', 'M', 'B', 'T'); 

    i <- findInterval(x, intl); 

    result <- character(length(x)); 

    # Note: for ggplot2 the last label element of x is NA, so we need to handle it 
    ind_format <- !is.na(x) & i > 0; 

    # Format only the elements that need to be formatted 
    # with suffixes and possible rounding 
    result[ind_format] <- paste0(
     formatC(x[ind_format]/intl[i[ind_format]], format = "f", digits = digits) 
     ,suffixes[i[ind_format]] 
    ); 
    # And leave the rest with no changes 
    result[!ind_format] <- as.character(x[!ind_format]); 

    return(invisible(result)); 
} 

使用示例。

x <- seq(1:10); 
d <- data.frame(x = x, y = 10^x); 
ggplot(aes(x=x, y=y), data = d) + geom_line() + scale_y_log10() 

without suffix formatter

ggplot(aes(x=x, y=y), data = d) + geom_line() + scale_y_log10(labels = suffix_formatter) 

with suffix formatter