Displaying 1 result from an estimated 1 matches for "willdo".
2008 Jun 27
3
cumulative sum of within levels of a dataframe
...a
4 1 a
5 1 a
6 2 b
7 2 b
8 2 b
9 2 b
10 2 b
11 3 c
12 3 c
13 3 c
14 3 c
15 3 c
I'd like to create another column in the dataframe so it looks like this,
and make sure that the cumulative sums still match the right levels of the
factor. I've included a "willdo" column that's just a cumulative sum, and
an "ideal" column that's the cumulative sum minus the current value - the
column headings are self explanatory.
> answer
x fac willdo ideal
1 1 a 1 0
2 1 a 2 1
3 1 a 3 2
4 1 a 4 3...