[R] partially sum variable of a dataframe

John Kane jrkrideau at yahoo.ca
Wed Nov 7 15:25:12 CET 2007


d <- subset(c, c$a > 3 & c$a < 5.25 )
sum(d[,2])

--- mdgi at gmx.ch wrote:

> Hello,
> 
> A stupid question:
> 
> I have an array with two columns, the first "a"
> acting as my index in 0.25 steps, the second one "b"
> the column of interest. How can i sum up "b" only
> for a specified window in "a" (as the window command
> for time series)
> 
> a=seq(0,10,0.25)
> b=runif(41)
> c=data.frame(a,b)
> 
> Sum up c if 3<a<5.25
> 
> How to do that? thanks
> 
> marc
> -- 
> Psssst! Schon vom neuen GMX MultiMessenger gehört?
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> 
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