[R] data frame cumulative row sum
r.turner at auckland.ac.nz
Mon Dec 8 21:40:19 CET 2014
On 08/12/14 21:18, Ragia Ibrahim wrote:
> Kindly I had a data frame looks like this
> x y
> 1 3
> 2 2
> 3 1
> 4 3
> and I want to add column z that sum cumulativly like this
> x y z
> 1 3 3
> 2 2 5
> 3 1 6
> 4 3 9
> how to do this?
(1) Learn to use R. This is very basic; read some introductory
material. Start with "An Introduction to R" from the R web site.
This is analogous to the assertion that you shouldn't be driving a car
if you haven't a clue how to drive.
X$z <- cumsum(X$y)
where X is the data frame in question.
Technical Editor ANZJS
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