[R] Adding variables

[Gabor Grothendieck]

Note that Henrique's code does not give the same result as the
expression you posted although its possible that his is what you
really intended.

On Sun, Sep 27, 2009 at 10:27 AM, tzygmund mcfarlane
<tzygmund at googlemail.com> wrote:
> 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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>>>
>>
>