[R] Adding variables

[tzygmund mcfarlane]

Thank you Gabor (& Henrique)!

On Sun, Sep 27, 2009 at 3:26 PM, Gabor Grothendieck
<ggrothendieck at gmail.com> wrote:
> with(attenu, mag + as.numeric(station))
>
> is nearly twice as fast:
>
>> system.time(for(i in 1:1000) with(attenu, mag + as.numeric(station)))
>   user  system elapsed
>   0.05    0.02    0.06
>
>> system.time(for(i in 1:1000) rowSums(cbind(mag, station)))
>   user  system elapsed
>   0.09    0.00    0.10
>
> See ?system.time, ?Rprof and http://code.google.com/p/rbenchmark/
> for timing commands.
>
> On Sat, Sep 26, 2009 at 11:16 AM, tzygmund mcfarlane
> <tzygmund at googlemail.com> wrote:
>> Hi,
>>
>> For very large matrices, is this the most efficient way to add two
>> variables together?
>>
>> #############################
>> attach(attenu)
>> new<-rowSums(cbind(mag, station))
>> #############################
>>
>> Also, could I be directed to some resources for working with very
>> large datasets?
>>
>> Thanks
>>
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>> and provide commented, minimal, self-contained, reproducible code.
>>
>