[R] match function or "=="

Patrick Burns pburns at pburns.seanet.com
Wed Apr 7 21:07:50 CEST 2010

You might want to investigate the
'data.table' package.

On 07/04/2010 16:15, bo wrote:
> Hi all,
> I have a huge dataset(5000k observations), which contains the daily sales
> for each company.
> If I want to find out the a company with unique company id number, which
> function I should use that is more efficient, match or "=="?  For example,
> use<-dataset[!is.na(match(dataset$companyID, 12345)),]
> or
> use<-dataset[dataset$companyID==12345,]
> Thank you very much.

Patrick Burns
pburns at pburns.seanet.com
(home of 'Some hints for the R beginner'
and 'The R Inferno')

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