Dear Mark,
Try this:

lapply(yourlistofdataframes, function(d){
                   k <- ncol(d)
                   d$product <- d[,k-1] * d[,k]
                   d
                    }
           )

HTH,

Jorge


On Thu, Jul 23, 2009 at 2:05 PM, Mark Na <mtb954@gmail.com> wrote:

> Hi R-helpers,
>
> I have a list containing 10 elements, each of which is a dataframe. I wish
> to add a new column to each list element (dataframe) containing the product
> of the last two columns of each dataframe.
>
> I'd appreciate any pointers, thanks!
>
> Mark Na
>
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>
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