Please review my app logic - R Newb [closed]

Answer 1

You're logic is a bit problematic, especially how you're using rows. Let's say you want to do it for column 1 of the data.frame dat.

n <- nrow(dat)
y <- dat[1:(n-1),1] < dat[2:n,1]
y <- c(FALSE, y) # we know the first one is false because there's nothing before

Answer 2

You don't really define what you mean by a row being greater than another (for instance, what if the first column is larger and the second column is smaller?). However, if you wanted to determine if each successive element in a column of your data is smaller than the next, you could use the diff function:

dfSource$larger <- c(diff(dfSource[,1]) > 0, FALSE)
dfSource
#      X1 X2 X3 larger
# row1  1  2  3  FALSE
# row2  1  2  3   TRUE
# row3  2  3  4  FALSE
# row4  2  3  4  FALSE