decimal_places() counts the decimal places in a numeric
vector, or in a string vector that can be coerced to numeric.
decimal_places_scalar() is much faster but only takes a single input. It
is useful as a helper within other single-case functions.
Details
Decimal places in numeric values can't be counted accurately if the number has 15 or more characters in total, including the integer part and the decimal point. A possible solutions is to enter the number as a string to count all digits. (Converting to string is not sufficient – those numbers need to be entered in quotes.)
The functions ignore any whitespace at the end of a string, so they won't mistake spaces for decimal places.
Trailing zeros
If trailing zeros matter, don't convert numeric
values to strings: In numeric values, any trailing zeros have already been
dropped, and any information about them was lost (e.g., 3.70 returns
3.7). Enter those values as strings instead, such as "3.70" instead of
3.70. However, you can restore lost trailing zeros with
restore_zeros() if the original number of decimal places is known.
If you need to enter many such values as strings, consider using
tibble::tribble() and drawing quotation marks around all values in a
tribble() column at once via RStudio's multiple cursors.
See also
decimal_places_df(), which applies decimal_places() to all
numeric-like columns in a data frame.
Examples
# `decimal_places()` works on both numeric values
# and strings...
decimal_places(x = 2.851)
#> [1] 3
decimal_places(x = "2.851")
#> [1] 3
# ... but trailing zeros are only counted within
# strings:
decimal_places(x = c(7.3900, "7.3900"))
#> [1] 2 4
# This doesn't apply to non-trailing zeros; these
# behave just like any other digit would:
decimal_places(x = c(4.08, "4.08"))
#> [1] 2 2
# Whitespace at the end of a string is not counted:
decimal_places(x = "6.0 ")
#> [1] 1
# `decimal_places_scalar()` is much faster,
# but only works with a single number or string:
decimal_places_scalar(x = 8.13)
#> [1] 2
decimal_places_scalar(x = "5.024")
#> [1] 3