R, Cumsum function on non-concatinative variable realisations

Question

I have a 306x19 data-set and I would like to use the Cumsum function on say, VarF only when VarA takes a certain value.

On a high-level description, the idea is to filter on VarA and apply a cumsum on the remaining of the dataset (VarF).

I would appreciate any pointers here guy on how to solve this.

This is trivial using subsetting ... – Roland Nov 14 '16 at 20:10 — Roland, Nov 14 '16 at 20:10
I would be interested to know how. Thanks – SolitonK Nov 14 '16 at 20:41 — SolitonK, Nov 14 '16 at 20:41

score 0 · Accepted Answer · edited Nov 14 '16 at 20:22

0

Have you tried using the ifelse function? Something like this should work:

cumsum(ifelse(VarA == value, VarF, 0))

edited Nov 14 '16 at 20:22

demongolem

answered Nov 14 '16 at 20:11

F. Caru

1 Answers1