> #just to have some data
> testdata<-matrix(rnorm(14*7),ncol=14)
> testframe<-as.data.frame.matrix(testdata)
> names(testframe)<-c("Year","Series","Age","WM",
"WF","HM","HF","BM","BF","IM","IF","AM","AF","Yr")
> #one way is colSums
> colSums(testframe)[c(3,5,8,10)]
         Age           WF           BM           IM 
 5.024714070  1.974526477  0.004256433 -2.940214886 
> #another way is a for loop
> testvector<-rep(NA,14)
> for (i in 1:14) testvector[i]<-sum(testframe[,i])
> testvector[c(3,5,8,10)]
[1]  5.024714070  1.974526477  0.004256433 -2.940214886
> #there are other ways:)



<snip>
 for(i in 4:13){
sumVar<- sum(popA[,i])
sumVar2<-c(sumVar) 
}
<end snip>
You are replacing sumVar in each iteration of the loop, not creating a new
element.

bob



-----Original Message-----
From: Siddique, Amer [mailto:Amer.Siddique@ssa.gov] 
Sent: Friday, July 18, 2003 4:02 PM
To: 'r-help@stat.math.ethz.ch'
Subject: [R] create a vector looping over a frame 

Hello,

I have a data.frame

> names(popA)
 [1] "Year"   "Series" "Age"    "WM"     "WF"     "HM"     "HF"     "BM"    
 [9] "BF"     "IM"     "IF"     "AM"     "AF"     "Yr"  

how do i loop over a subset of variables in this frame to create a vector of
length equal to the number of variables in the subset such that the vector's
ith element is the result of an aggregate fncn applied to the ith variable?

eg,
sumvar<-c(sum(WM),...,sum(AF))

if i try

for(i in 4:13){
sumVar<- sum(popA[,i])
sumVar2<-c(sumVar) 
}

it returns 

> sumVar2
[1] 287567

> length(sumVar2)
[1] 1

which is only the value at the last spot. i cant quite figure this simple
loop. 

Thanks,

Amer Siddique

______________________________________________
R-help@stat.math.ethz.ch mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help

	[[alternative HTML version deleted]]


