Format numeric values by significant figures.

Format numeric values by significant figures with controllable round_type, whole_integer and trailing zeros.
The underlying function for significant figures is modified_signif_j(), which is a modified version for base::signif()

Usage

format_sigfig_j(
  sigfig,
  format = "xx",
  whole_integer = TRUE,
  zero_threshold = 10^(-2 * sigfig),
  drop0trailing = FALSE
)

modified_signif_j(
  x,
  digits = 6,
  round_type = valid_round_type,
  whole_integer = FALSE,
  zero_threshold = 0
)

Arguments

sigfig

(integer(1))
number of significant figures to display.

format

(character(1))
layout format string controlling how one or two values are arranged, e.g. "xx", "xx (xx)", "(xx, xx)". Any decimal specification in xx. or xx.x+ is stripped — precision is controlled by sigfig alone.

whole_integer

(logical(1))
if TRUE, all significant figures to the left of the decimal marker can be shown. If FALSE, the specified number of significant figures is shown.

zero_threshold

(numeric(1))
very small absolute values (abs(x) < zero_threshold) can be treated as zero. Defaults to 0 (values are left as is).

drop0trailing

(logical(1))
indicating if trailing zeros, i.e., "0" after the decimal mark, should be removed
argument is passed to function formatC

x

(numeric)
numbers to round.

digits

(integer(1))
number of significant figures to display.

round_type

(character(1))
rounding method, passed onto formatters::round_fmt(). See formatters::format_value() for details.

Value

A formatting function with signature function(x, round_type, ...) that returns a formatted string. The round_type argument accepts rounding methods ("iec", "iec_mod", "sas") (see formatters::round_fmt()).

Functions

• format_sigfig_j(): A function factory that produces formatting functions to round values to a specified number of significant figures, suitable for use with formatters::format_value().
  
  The function is an alternative to tern::format_sigfig(), format_sigfig_j() has fixed the formatC argument num_fmt = "fg", and has extra options for whole_integer and drop0trailing to control the format behavior.

• modified_signif_j(): A modified version of base function base::signif with 3 extensions:

  • Rounding is performed using formatters::round_fmt(), and allows for round types ("iec", "iec_mod", "sas")
    

  • Very small absolute values can be treated as zero (zero_threshold).
    

  • All significant figures to the left of the decimal marker can be shown (whole_integer), rather than limiting the result to the specified number of significant figures.

  Returns a numeric vector of the same length as x, rounded to digits significant figures.

See also

tern::format_sigfig()

Examples

fmt <- format_sigfig_j(3)
fmt(0.001234)
#> [1] "0.00123"
fmt(1234.5)
#> [1] "1234"

fmt2 <- format_sigfig_j(3, format = "xx (xx)")
fmt2(c(1234.5, 0.00567))
#> [1] "1234 (0.00567)"


format_sigfig_j(3, drop0trailing = FALSE)(0.01)
#> [1] "0.0100"
format_sigfig_j(3, drop0trailing = TRUE)(0.01)
#> [1] "0.01"
# example code
junco:::modified_signif_j(c(0.1, 1e-9, 1256.0, 1256.5, 1256.3, 1254.5, 1256.5),
  digits = 3,
  zero_threshold = 0,
  whole_integer = TRUE,
  round_type = "sas"
)
#> [1] 1.000e-01 1.000e-09 1.256e+03 1.257e+03 1.256e+03 1.255e+03 1.257e+03

junco:::modified_signif_j(c(0.1, 1e-9, 1256.0, 1256.5, 1256.3, 1254.5, 1256.5),
  digits = 3,
  zero_threshold = 1e-6,
  whole_integer = TRUE,
  round_type = "sas"
)
#> [1]    0.1    0.0 1256.0 1257.0 1256.0 1255.0 1257.0