first row where value in one column higher than in another column R

I have a data table:

df <- data.table(Points = 1:5, A = c(2,4,6,8,10), B = c(1,3,4,5,9))  df <-   Points  A B    1     2 1    2     4 3    3     6 4    4     8 5    5    10 9  

I want the value of column Points corresponding to the first value in column B that is higher than the current value of column A.

Expected output if A == 4:

4 (the first value in B bigger than 4 has a corresponding value of Points equal to 4)

https://stackoverflow.com/questions/67410227/first-row-where-value-in-one-column-higher-than-in-another-column-r May 06, 2021 at 08:02AM