Within an R data.table can you add multiple columns using conditional statements? -

I would like to add a column to a column based on the values ​​of the other columns in one column, e.g.

  df < - data.frame (a = c (1,2,3), b = c (4,5,1)), & lt; - Data Eligible (df) G & LT; - Function (x, y) {if (y> gt) returns (list (1,2)) and return (list (2,1)) dt [, c ('x', 'y') = G (A, B)]  

But these errors arise, and using IFLs does not work either.

you if (...) else Should use ifelse instead. In addition there should be a list of length of return statement, in which each list element has the same length as x and y .

  live < - Function (x, y) {list (ifelse (y>, x, 1, 2), ifelse (y> x, 2, 1))}  

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