Using if else on a dataframe across multiple columns

Question

I have a large dataset of samples with descriptors of whether the sample is viable - it looks (kind of) like this, where \'desc\' is the description column and \'blank\' ind

Answer 1

Here's another dplyr solution with a small custom function and mutate_each().

library(dplyr)

f <- function(x) if_else(dat$desc == "blank", NA_real_, x)
dat %>% 
  mutate_each(funs(f), -desc)
#>      desc        x        y        z
#> 1   blank       NA       NA       NA
#> 2   blank       NA       NA       NA
#> 3  sample 3.624941 6.430955 5.486632
#> 4  sample 3.236359 4.935453 4.319202
#> 5   blank       NA       NA       NA
#> 6   blank       NA       NA       NA
#> 7   blank       NA       NA       NA
#> 8  sample 5.058725 6.751650 4.750529
#> 9  sample 5.837206 4.323562 4.914780
#> 10  blank       NA       NA       NA