Find first non-missing element

Given a set of vectors, coalesce() finds the first non-missing value at each position. This is inspired by the SQL COALESCE function which does the same thing for NULLs.

coalesce(...)

Arguments

...	<dynamic-dots> Vectors. Inputs should be recyclable (either be length 1 or same length as the longest vector) and coercible to a common type. If data frames, they are coalesced column by column.

Value

A vector the same length as the first ... argument with missing values replaced by the first non-missing value.

See also

na_if() to replace specified values with a NA. tidyr::replace_na() to replace NA with a value

Examples

# Use a single value to replace all missing values
x <- sample(c(1:5, NA, NA, NA))
coalesce(x, 0L)
#> [1] 5 4 3 0 2 0 1 0

# Or match together a complete vector from missing pieces
y <- c(1, 2, NA, NA, 5)
z <- c(NA, NA, 3, 4, 5)
coalesce(y, z)
#> [1] 1 2 3 4 5

# Supply lists by with dynamic dots
vecs <- list(
  c(1, 2, NA, NA, 5),
  c(NA, NA, 3, 4, 5)
)
coalesce(!!!vecs)
#> [1] 1 2 3 4 5