I am coming from the perspective of Excel and VBA scripts, but I would like to do the following in R. I have a data frame with 14 columns and 32,795 rows. I want to check the value in column 8 (row 1) to see if it is a 0. If it is not a zero, proceed to the next row and check the value for column 8. If it is a zero, then a) change the zero to a 1, b) divide the value in column 9 (row 1) by 1, c) place the result in column 10 (row 1) and d) repeat this for each of the other 32,794 rows. Is this possible with an R script, and is this the way to go about it. If it is, could anyone get me started ? Matthew