# st: RE: Re: RE: Creating a variable (cumulative revenue by title)

 From "Nick Cox" To Subject st: RE: Re: RE: Creating a variable (cumulative revenue by title) Date Tue, 10 Feb 2009 21:00:13 -0000

```Correct. But Mike's example was in general clear.

Nick
n.j.cox@durham.ac.uk

Martin Weiss

"I take it that references to -wkndrev- in your examples are typos. "

As are the ones to "week"... Grrrr...

From: "Nick Cox" <n.j.cox@durham.ac.uk>

>I take it that references to -wkndrev- in your examples are typos.
>
> Here is one way to do it:
>
> bysort title wk : egen crevall = total(wkrev)
> by title wk : gen tag = _n == 1
> by title : replace crevall = sum(tag * crevall)
>
> Nick
> n.j.cox@durham.ac.uk
>
> Mike Kim
>
> I have a question about creating a variable. The structure of my data
is
> a
> little complicated. Here is an example.
>
> wk title country wkrev crevc wkrevall crevall
> 1     X     A         10     10    10     10
> 2     X     A         20     30     20     30
> 4     X     A         30     60     30     60
> 5     X     B         40     40     40     100
> 1     Y     C         10     10     30     30
> 1     Y     D         20     20     30     30
> 2     Y     C         30     40     70     100
> 2     Y     D         40     60     70     100
> 4     Y     E         50     50     50     150
>
> wk=week
> wkrev=weekly revenue
> crevc=cumulative revenue from each country up to the week (by title)
> wkrevall=weekly revenue from all countries for each week (by title)
> crevall=cumulative revenue from all country up to the week (by title)
>
> My question is: how can I create the last variable "crevall"?
>
> I created 'crevc' and 'wkrevall' by the following:
>
> sort title country week
> by title country: gen crevc=sum(wkndrev)
>
> sort title week country
> by title week: egen wkrevall=total(wkndrev)

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```