[R] Data Parameter extract

[David Winsemius]

On Oct 14, 2010, at 8:56 PM, joeman3285 wrote:

>
> Hi,
> So I have a set of data, hourly temperature, where each temperature  
> is set
> up like this:
>
> Time     Temp
> 1.04        8
> 1.08        10
>
> etc.  Where "1" corresponds to a day (say monday is "1", tuesday is  
> "2") and
> the decimal value corresponds to an the hour of the day.
>
> I have several thousand of these readings over several months.  What  
> I would
> like to do is extract daily minimum temperatures from this data set.

>  Is this possible to do with R?
>
> I'm pretty new to the use of R and have only a basic understanding  
> of how it
> all works.

One way that works best is for questions to include data in an R  
object. If those values are in a data.frame, dfrm, (and if they're  
not, then you need to work through some examples in the Introduction  
to R and the Import/Export Manual)  then:

dput(head(dfrm, 20)) # would get a version of the data that anyone  
could paste into their console.

Still assuming you have this in a data.frame, perhaps:

mintemps <- with( dfrm, tapply( Temp, floor(Time) , min) )
mintemps

>
> I appreciate any help.
>
> -joe
> -- 
> View this message in context: http://r.789695.n4.nabble.com/Data-Parameter-extract-tp2996369p2996369.html
> Sent from the R help mailing list archive at Nabble.com.
######
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-- 
David Winsemius, MD
West Hartford, CT