Good K/M/G abbreviation of y scale labels in ggplot2

Question

How can we easily have Kilo/Mega/Giga labels without "bits" or "Bytes" unit symbols?

Example

data.frame(x = LETTERS[1:5], n = c(0, 5000, 10000, 15000, 20000)) %>% 
  ggplot(aes(x, n)) + 
  geom_point() +
  scale_y_continuous(labels = scales::number_bytes_format(units = "si"))

For the y scale I expect the labels 0K, 5K, 10K, 15K, 20K. No Kb!

Bonus question

Is there any available solution to get 0, 1K, 1M, 1G labels? I.e., the most appropriate abbreviation of the values?

Try gdata::humanReadable:

library(ggplot2)
library(gdata)

myDat <- data.frame(x = LETTERS[1:5], n = c(0, 5000, 10000, 15000, 20000))

ggplot(myDat, aes(x, n)) + 
  geom_point() +
  scale_y_continuous(breaks = myDat$n, 
                     labels = humanReadable(myDat$n, standard = "Unix", sep = ""))

---

Edit:

We could customise the function:

humanReadableCustom <- function (x, units = "auto", standard = c("IEC", "SI", "Unix"), 
                                 digits = 1, width = NULL, sep = " ", justify = c("right", 
                                                                                  "left")) 
{
  #suffix.SI <- c("B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB")
  # custom
  suffix.SI <- c("", "K", "M", "G", "T", "P", "E", "Z", "Y")

  suffix.IEC <- c("B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB")
  suffix.Unix <- c("B", "K", "M", "G", "T", "P", "E", "Z", "Y")
  standard <- match.arg(standard)
  if (length(justify) == 1) 
    justify <- c(justify, justify)
  .applyHuman <- function(x, base, suffix, digits, width, 
                          sep) {
    n <- length(suffix)
    i <- pmax(pmin(floor(log(x, base)), n - 1), 0)
    if (!is.finite(i)) 
      i <- 0
    x <- x/base^i
    if (is.null(width)) 
      x <- format(round(x = x, digits = digits), nsmall = digits)
    else {
      lenX <- nchar(x)
      if (lenX > width) {
        digits <- pmax(width - nchar(round(x)) - 1, 
                       0)
      }
      if (i == 0) 
        digits <- 0
      x <- round(x, digits = digits)
    }
    c(x, suffix[i + 1])
  }
  if (any(x < 0)) 
    stop("'x' must be positive")
  if (standard == "SI") {
    suffix <- suffix.SI
    base <- 10^3
  }
  else if (standard == "IEC") {
    suffix <- suffix.IEC
    base <- 2^10
  }
  else {
    suffix <- suffix.Unix
    base <- 2^10
  }
  if (!missing(units) && units == "bytes") {
    retval <- rbind(x, "bytes")
  }
  else if (!missing(units) && units != "auto") {
    units <- suffix[match(toupper(units), toupper(suffix))]
    power <- match(units, suffix) - 1
    X <- x/(base^power)
    X <- format.default(x = X, digits = digits, nsmall = digits)
    retval <- rbind(X, rep(units, length(X)))
  }
  else retval <- sapply(X = x, FUN = ".applyHuman", base = base, 
                        suffix = suffix, digits = digits, width = width, sep = sep)
  if (all(justify == "none")) 
    paste(trim(retval[1, ]), trim(retval[2, ]), sep = sep)
  else paste(format(trim(retval[1, ]), justify = justify[1]), 
             format(trim(retval[2, ]), justify = justify[2]), sep = sep)
}

Then plot

library(ggplot2)
library(gdata)

myDat <- data.frame(x = LETTERS[1:5], n = c(0, 5000, 10000, 15000, 20000))

ggplot(myDat, aes(x, n)) + 
  geom_point() +
  scale_y_continuous(breaks = myDat$n, 
                     labels = humanReadableCustom(myDat$n,
                                                  standard = "SI", sep = ""))