humanReadable {gdata} | R Documentation |
humanReadable
converts byte size in human readable format such as
kB, MB, GB, etc.
humanReadable(x, standard="SI", digits=1, width=3, sep=" ")
x |
integer, byte size |
standard |
character, "SI" for powers of 1000 or anything else for powers of 1024, see details |
digits |
integer, number of digits after decimal point |
width |
integer, width of number string |
sep |
character, separator between number and unit |
Basic unit used to store information in computers is a bit. Bits are represented as zeroes and ones - binary number system. Although, the binary number system is not the same as the decimal number system, decimal prefixes for binary multiples such as kilo and mega are often used. In the decimal system kilo represent 1000, which is close to 1024 = 2^{10} in the binary system. This sometimes causes problems as it is not clear which powers (2 or 10) are used in a notation like 1 kB. To overcome this problem International Electrotechnical Commission (IEC) has provided the following solution to this problem:
Name | System | Symbol | Size | Conversion |
byte | binary | B | 2^3 | 8 bits |
kilobyte | decimal | kB | 10^3 | 1000 bytes |
kibibyte | binary | KiB | 2^{10} | 1024 bytes |
megabyte | decimal | MB | (10^3)^2 | 1000 kilobytes |
mebibyte | binary | MiB | (2^{10})^2 | 1024 kibibytes |
gigabyte | decimal | GB | (10^3)^3 | 1000 megabytes |
gibibyte | binary | GiB | (2^{10})^3 | 1024 mebibytes |
terabyte | decimal | TB | (10^3)^4 | 1000 gigabytes |
tebibyte | binary | TiB | (2^{10})^4 | 1024 gibibytes |
petabyte | decimal | PB | (10^3)^5 | 1000 terabytes |
pebibyte | binary | PiB | (2^{10})^5 | 1024 tebibytes |
exabyte | decimal | EB | (10^3)^6 | 1000 petabytes |
exbibyte | binary | EiB | (2^{10})^6 | 1024 pebibytes |
zettabyte | decimal | ZB | (10^3)^7 | 1000 exabytes |
zebibyte | binary | ZiB | (2^{10})^7 | 1024 exbibytes |
yottabyte | decimal | YB | (10^3)^8 | 1000 zettabytes |
yebibyte | binary | YiB | (2^{10})^8 | 1024 zebibytes |
where Zi and Yi are GNU extensions to IEC. To get the output in the decimal
system (powers of 1000) use standard="SI"
. Otherwise IEC standard
(powers of 1024) is used.
For printout both digits
and width
can be specified. If
width
is NULL
, all values have given number of digits. If
width
is not NULL
, output is rounded to a given width and
formated similar to human readable format of ls
, df
or
du
shell commands.
Byte size in human readable format as character with proper unit symbols added at the end of the string.
Ales Korosec and Gregor Gorjanc
Wikipedia: http://en.wikipedia.org/wiki/Byte http://en.wikipedia.org/wiki/SI_prefix http://en.wikipedia.org/wiki/Binary_prefix
GNU manual for coreutils: http://www.gnu.org/software/coreutils/manual/html_node/Block-size.html#Block-size
baseSI <- 10 powerSI <- seq(from=3, to=27, by=3) SI0 <- (baseSI)^powerSI k <- length(SI0) - 1 SI1 <- SI0 - SI0 / c(2, runif(n=k, min=1.01, max=5.99)) SI2 <- SI0 + SI0 / c(2, runif(n=k, min=1.01, max=5.99)) baseIEC <- 2 powerIEC <- seq(from=10, to=90, by=10) IEC0 <- (baseIEC)^powerIEC IEC1 <- IEC0 - IEC0 / c(2, runif(n=k, min=1.01, max=5.99)) IEC2 <- IEC0 + IEC0 / c(2, runif(n=k, min=1.01, max=5.99)) cbind(humanReadable(x=SI1, width=NULL, digits=3), humanReadable(x=SI0, width=NULL, digits=2), humanReadable(x=SI2, width=NULL, digits=1), humanReadable(x=IEC1, standard="IEC", width=7, digits=3), humanReadable(x=IEC0, standard="IEC", width=7, digits=2), humanReadable(x=IEC2, standard="IEC", width=7, digits=1))