Utility functions — min_or_na • ICU data with R

Several utility functions exported for convenience.

min_or_na(x)

max_or_na(x)

is_val(x, val)

not_val(x, val)

is_true(x)

is_false(x)

last_elem(x)

first_elem(x)

Arguments

x: Object to use
val: Value to compare against or to use as replacement

Value

min_or_na()/max_or_na(): scalar-valued extrema of a vector
is_val()/not_val()/is_true()/is_false(): Logical vector of the same length as the object passed as x
first_elem()/last_elem(): single element of the object passed as x
replace_na(): modified version of the object passed as x

Details

The two functions min_or_na() and max_or_na() overcome a design choice of base::min() (or base::max()) that can yield undesirable results. If called on a vector of all missing values with na.rm = TRUE, Inf(and-Infrespectively) are returned. This is changed to returning a missing value of the same type asx`.

The functions is_val() and not_val() (as well as analogously is_true() and is_false()) return logical vectors of the same length as the value passed as x, with non-base R semanticists of comparing against NA: instead of returning c(NA, TRUE) for c(NA, 5) == 5, is_val() will return c(FALSE TRUE). Passing NA as val might lead to unintended results but no warning is thrown.

Finally, first_elem() and last_elem() has the same semantics as utils::head() and utils::tail() with n = 1L and replace_na() will replace all occurrences of NA in x with val and can be called on both objects inheriting from data.table in which case internally data.table::setnafill() is called or other objects.

Examples

some_na <- c(NA, sample(1:10, 5), NA)
identical(min(some_na, na.rm = TRUE), min_or_na(some_na))
#> [1] TRUE

all_na <- rep(NA, 5)
min(all_na, na.rm = TRUE)
#> Warning: no non-missing arguments to min; returning Inf
#> [1] Inf
min_or_na(all_na)
#> [1] NA

is_val(some_na, 5)
#> [1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE
some_na == 5
#> [1]    NA FALSE FALSE FALSE FALSE FALSE    NA

is_val(some_na, NA)
#> [1] FALSE    NA    NA    NA    NA    NA FALSE

identical(first_elem(letters), head(letters, n = 1L))
#> [1] TRUE
identical(last_elem(letters), tail(letters, n = 1L))
#> [1] TRUE

replace_na(some_na, 11)
#> [1] 11  7  1 10  4  6 11
replace_na(all_na, 11)
#> [1] TRUE TRUE TRUE TRUE TRUE
replace_na(1:5, 11)
#> [1] 1 2 3 4 5

tbl <- ts_tbl(a = 1:10, b = hours(1:10), c = c(NA, 1:5, NA, 8:9, NA))
res <- replace_na(tbl, 0)
identical(tbl, res)
#> [1] FALSE