apply function that takes row as an argument to each row in data.table

Question

I have a data.table dt = structure(list(x = 1:3, y = 3:5), .Names = c("x", "y"), row.names = c(NA, -3L), class = c("data.table", "data.frame"))

Also, I have a given function that takes a row and dataset as an argument. For example, lets

function_sum <- function(i, dataset){
  x <- as.numeric(dataset[i,1])
  y <- as.numeric(dataset[i,2])
  x+y
}

I need to apply this function to each row in my dataset and have no idea how to do it.

It doesn't work dt[, function_sum(i=.SDrow, dataset=dt), by = seq_len(nrow(dt))]

Answer 1

Using your function_sum() function:

sapply(1:nrow(dt), function(i) function_sum(i,dt))
#[1] 4 6 8