first_non_nas {tidytidbits}

Row-wise first value which is not NA

Description

This is useful in conjunction with dplyr's mutate to condense multiple columns to one, where in each sample typically only one of n columns has a value, while the others are NA. Returns one vector of the same length as each input vector containing the result. Note that factors will be converted to character vectors (with a warning).

Usage

first_non_nas(...)

Arguments

...

multiple vectors of same type and size, regarded as columns

Value

Returns a vector of type and size as any of the given vectors (vectors regarded a column, number of rows is size of each vectors) For each "row", returns the first value that is not NA, or NA iff all values in the row are NA.

Examples

library(tibble)
library(magrittr)
library(dplyr)
# Creates a column containing (4, 2, 2)
tibble(a=c(NA, NA, 2), b=c(4, NA, 5), c=c(1, 2, 3)) %>%
  mutate(essence=first_non_nas(a, b, c))