Count decimal places

decimal_places() counts the decimal places of numbers, or of numbers written as strings.

Usage

decimal_places(x, sep = ".")

Arguments

x

Numeric, or strings that contain numbers.

sep

String. The separator between the integer part and the decimal places, matched literally. Default is ".". Only applies to strings; numbers are always written with a point.

Value

Integer. The number of decimal places of each element of x.

Details

The function counts the run of digits after the first sep, after trimming whitespace and applying any exponent: "5.30%" has two decimal places, "1e-5" has five, and "1..5" has none. Missing and non-finite values have NA decimal places, as do the string "NA", a blank string, and strings that as.numeric() reads as an infinity or NaN.

Numeric values with more than 15 significant digits cannot be counted accurately; enter such numbers as strings.

Trailing zeros

A numeric value has lost its trailing zeros: 3.70 is stored as 3.7 and has one decimal place. If trailing zeros matter, count them while the values are still strings, such as "3.70", and give the counts to the tests as digits_x or digits_sd, as in dplyr::mutate(data, digits_x = decimal_places(x), x = as.numeric(x)).

Examples

decimal_places(x = 2.851)
#> [1] 3
decimal_places(x = "2.851")
#> [1] 3

# Trailing zeros are only counted in strings:
decimal_places(x = c(7.3900, "7.3900"))
#> [1] 2 4

# Whitespace at the end of a string is ignored:
decimal_places(x = "6.0     ")
#> [1] 1