[R] factor as seq() in for loop

[Tord Snall]

Dear all,
I would like to use the values in vegaggr.BLMCMR02$colony 

str(vegaggr.BLMCMR02)
`data.frame':   1678 obs. of  3 variables:
$ vegtype       : Factor w/ 27 levels "2010","2020",..: 3 4 5 19 4 5 19 5  
$ colony        : Factor w/ 406 levels "0","1","10","100",..: 1 1 1 1 2 2 2 
$ Totvegproparea: num  0.00055 0.03956 0.95705 0.00284 0.05215 ...

as the seq in a for loop (for(var in seq)), and therefore first picked them 
out as 
cols = aggregate(list(A = vegaggr.BLMCMR02$Totvegproparea), 
                list(colony = vegaggr.BLMCMR02$colony), sum)[,1]
> str(cols)
 Factor w/ 406 levels "0","1","10","100",..: 1 2 3 4 5 6 7 8 9 10 ...

I next planned to transform cols using as.integer(cols). However, this 
transformation gives a vector corresponding to seq(from=1,to=length(cols)). 

Could someone please give advice on how to make use of a factor as the seq 
in a for loop (which is strictly not allowed' according to ?Control).

Thanks!

Tord