[R] data management question

[David Winsemius]

On Feb 8, 2012, at 12:23 AM, Sebastián Daza wrote:

> Hi everyone,
> I would like to have a function to compute some values in a dataset.
> First, I have to define a value for the lx variable in row 1 (e.g.,
> 100,000), npx is a given proportion. lx of row 2 is equal to lx of row
> 1 times npx of row 1. I can do this row by row...
>
> data[1,"lx"]  <- 100000
> data[2,"lx"]  <- data[1,"lx"]*data[1,"npx"]
> data[3,"lx"]  <- data[2,"lx"]*data[2,"npx"]
> data[4,"lx"]  <- data[3,"lx"]*data[3,"npx"]
> ...
> data[19,"lx"]  <- data[18,"lx"]*data[18,"npx"]
>
> Any ideas about how to define this in a function or in a more  
> systematic way?
> Thank you in advance.
>

You should get in the habit of offering complete examples.

?cumprod would seem likely helpful.

-- 

David Winsemius, MD
West Hartford, CT