[R] Aggregate Help

[Phil Spector]

Ken -
    Try

   aggregate(Pilot$Count,list(Date=Pilot$Date,illness=Pilot$illness),sum)

If you don't want to keep typing "Pilot", use

   with(Pilot,aggregate(Count,list(Date=Date,illness=illness),sum))

Notice that the aggregated variable will be called "x" in the output
data frame from aggregate.

 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley
 					 spector at stat.berkeley.edu

On Thu, 19 Aug 2010, Hall, Ken (CDC/OSELS/NCPHI) wrote:

> Please let me know if this is or is not the right place to ask these
> types of questions.
>
> Warning: I am new to R by two days.
>
> I have a simple dataset.
> I have loaded the dataset successfully using the following code:
>
> Filepath=(C:\temp\\pilot\dataset1.txt")
> Pilot=read.table(filepath, header=TRUE)
>
> Dataset1.txt is delimited and looks like this:
>
> Date	illness	count
> 2006/01/01	derm	17
> 2006/01/01	derm 	35
> 2006/01/02	derm	24
> 2006/01/02	derm	80
> .
> .
> .
> Total records like this approximately 18,000
>
> I would like to use the aggregate function to sum the count by similar
> date and illness, so it should look like this after the aggregate
>
> 2006/01/01	derm	52
> 2006/01/02	derm	104
> .
> .
> .
>
> And, the illness changes to fever with the same pattern. I would like to
> aggregate the same illnesses by date in the same fashion.
>
> A nudge in the right direction would be appreciated.
>
> Thanks.
>
> Ken Hall
> Computer Scientist
> Division of Healthcare Information (DHI) (proposed)
> Public Health Surveillance Program Office (proposed)
> Office of Surveillance, Epidemiology, & Laboratory Services (OSELS)
> (proposed)
> Centers for Disease Control & Prevention (CDC)
> kha6 at cdc.gov
> Mobile: 404-993-3311
> Office: 404-498-6839
>
>
>
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>
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