[R] how to calculate another vector based on the data from a combination of two factors

[Gabor Grothendieck]

Try this.  The first line appends the cumulative sum column and the second
displays it in sorted fashion:

DF$cumQuantity <- ave(DF$Quantity, DF$State, DF$Gender, FUN = cumsum)
DF[order(DF$State, DF$Gender), ]


On Sun, Nov 16, 2008 at 9:12 PM, jeffc <hcen at andrew.cmu.edu> wrote:
>
> Hi,
>
> I have a data set similar to the following
>
> State   Gender  Quantity
> TX      Male    1
> NY      Female  2
> TX      Male    3
> NY      Female  4
>
>
> I need to calculate cumulative sum of the quantity by State and Gender. The
> expected output is
> State   Gender  Quantity        CumQuantity
> TX      Male    1       1
> TX      Male    3       4
> NY      Female  2       2
> NY      Female  4       6
>
> I highly appreciate if someone can give me some hints on solving that in R.
>
> Hao
>
> --
> View this message in context: http://www.nabble.com/how-to-calculate-another-vector-based-on-the-data-from-a-combination-of-two-factors-tp20532749p20532749.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>