Style significant figure-like rounding

Converts a numeric argument into a string that has been rounded to a significant figure-like number. Scientific notation output is avoided, however, and additional significant figures may be displayed for large numbers. For example, if the number of significant digits requested is 2, 123 will be displayed (rather than 120 or 1.2x10^2).

Usage

style_sigfig(
  x,
  digits = 2,
  scale = 1,
  big.mark = ifelse(decimal.mark == ",", " ", ","),
  decimal.mark = getOption("OutDec"),
  ...
)

Arguments

x: Numeric vector
digits: Integer specifying the minimum number of significant digits to display
scale: (scalar numeric)
A scaling factor: x will be multiplied by scale before formatting.
big.mark: (string)
Character used between every 3 digits to separate hundreds/thousands/millions/etc. Default is ",", except when decimal.mark = "," when the default is a space.
decimal.mark: (string)
The character to be used to indicate the numeric decimal point. Default is "." or getOption("OutDec")
...: Arguments passed on to base::format()

Value

A character vector of styled numbers

Details

Scientific notation output is avoided.
If 2 significant figures are requested, the number is rounded to no more than 2 decimal places. For example, a number will be rounded to 2 decimals places when abs(x) < 1, 1 decimal place when abs(x) >= 1 & abs(x) < 10, and to the nearest integer when abs(x) >= 10.
Additional significant figures may be displayed for large numbers. For example, if the number of significant digits requested is 2, 123 will be displayed (rather than 120 or 1.2x10^2).

Author

Daniel D. Sjoberg

Examples

c(0.123, 0.9, 1.1234, 12.345, -0.123, -0.9, -1.1234, -132.345, NA, -0.001) %>%
  style_sigfig()
#>  [1] "0.12"  "0.90"  "1.1"   "12"    "-0.12" "-0.90" "-1.1"  "-132"  NA     
#> [10] "0.00"