Skip to content
Prev 325116 / 398503 Next

Speed up or alternative to 'For' loop

MacQueen, Don 
Sorry, it looks like I was hasty.
Absent another dumb mistake, the following should do it.

The request was for differences, i.e., the amount of growth from one
period to the next, separately for each tree.

for (ir in unique(df$TreeID)) {
  in.ir <- df$TreeID == ir
  df$HeightGrowth[in.ir] <- c(NA, diff(df$Height[in.ir]))
}



And this gives the same result as Rui Barradas' previous response.

-Don

Thread (7 messages)

Trevor Walker Speed up or alternative to 'For' loop Jun 10 Rui Barradas Speed up or alternative to 'For' loop Jun 10 MacQueen, Don Speed up or alternative to 'For' loop Jun 10 David Winsemius Speed up or alternative to 'For' loop Jun 10 MacQueen, Don Speed up or alternative to 'For' loop Jun 10 MacQueen, Don Speed up or alternative to 'For' loop Jun 10 arun Speed up or alternative to 'For' loop Jun 10