[R] How to deal with a dataframe within a dataframe?

[Gabor Grothendieck]

On Tue, May 8, 2012 at 9:19 AM, Robert Latest <boblatest at gmail.com> wrote:
> Hello all,
>
> I am doing an aggregation where the aggregating function returns not a
> single numeric value but a vector of two elements using return(c(val1,
> val2)). I don't know how to access the individual columns of that
> vector in the resulting dataframe though. How is this done correctly?
> Thanks, robert
>
>
>> agg <- aggregate(formula=df$value ~ df$quarter + df$tool,
> +     FUN=cp.cpk, lsl=1300, usl=1500)

Try this:

agg <- aggregate(value ~ quarter + tool, df,
     FUN=cp.cpk, lsl=1300, usl=1500)

do.call("data.frame", agg)

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