R: Flexible Formatting

formatC {base}

R Documentation

Flexible Formatting

Usage

formatC(x, digits = NULL, width = max(0, digits) + 1,
        format = NULL, flag = "", mode = NULL)

Arguments

`x`	an atomic numerical or character object, typically a vector of real numbers.
`digits`	the desired number of digits after the decimal point. Default: 2 for integer, 4 for real numbers. If less than 0, the C default of 6 digits is used.
`width`	the total field width; `width < 0` means left justify the number in this field (equivalent to `flag ="-"`). It is possible that the result will be longer than this, but that should only happen in reasonable cases.
`format`	equal to `"d"` (for integers), `"f"`, `"e"`, `"E"`, `"g"`, `"G"` (for reals), or `"s"` (for strings). `"f"` gives numbers in the usual “xxx.xxx” format; `"e"` and `"E"` give “n.dddenn” or “n.dddEnn” (scientific format); `"g"` and `"G"` put `x[i]` into scientific format only if it saves space to do so.
`flag`	format modifier as in Kernighan and Ritchie, 2nd ed., page 243. `"0"` pads leading zeros; `"-"` does left adjustment, others are `"+"`, `" "`, and `"#"`.
`mode`	`"real"`, `"integer"` or `"character"`. Default: Automatic.

Value

A character object of same size and attributes as x. Unlike format, each number is individually formatted. A for loop over each element of x, calling sprintf(...) is done in the C function str_signif.

For character arguments, simple (left or right) padding with white space is done.

Note

This function was originally written by Bill Dunlap and later much improved by Martin Maechler. It was adapted for R by Friedrich Leisch.

Examples

xx  <- pi * 10^(-5:4)
options(digits = 4)   # only for format
cbind(format(xx), formatC(xx))
cbind(formatC(xx, wid = 9, flag = "-"))
cbind(formatC(xx, dig = 5, wid = 8, format = "f", flag = "0"))

formatC(c("a", "Abc", "no way"), wid = -7)  # <=> flag = "-"