.. prefix to allow reference to parent-scoped variables in
library(data.table) v_names = c('a', 'b') DT = data.table(a = 1:3, b = 4:6, c = 7:9) # allows subsetting to 'a' and 'b' dynamically, # as a work-around to the default 'with' # behavior of data.table scoping DT[ , ..v_names]
If this is the complete script,
RStudio will throw a warning on the
vnames line if the “warn about unused variables” flag is on.