Loop problem

Dear all, I have a problem with a loop, if anyone has any knowledge on
these things I would appreciate some comments.  The code below is
designed to allow me to extract the top record of the data frame, and
them remove rows from the data frame which have an index close to the
extracted top record.


topstorm<-subset(rankeddataset[1,]) ## Extracts the top storm
topstormindex<-rankeddataset[1,1] ## Finds the top storm start index
startindex<-topstormindex-48 ## sets the start and end indexes
endindex<-topstorminde+48
rankeddataset<-rankeddataset[-1,] ## Creates a new list with the top
storm removed

##This section of code needs looped.  It removes storms from the list
which are too close to the extracted storm

for (i in 1:30){
if (rankeddataset[i,1]>startindex && rankeddataset[i,1]<endindex)
{rankeddataset<-rankeddataset[-i,]}
}

Here is some example data:

   82856  15 / 6 / 1966   82856:82879            25.9
   82857  15 / 6 / 1966   82857:82880            20.5
   83036  23 / 6 / 1966   83036:83059            17.3
   87250 15 / 12 / 1966   87250:87273            15.9

Hi again Jamie,
I had a bit of time tonight and recognized your problem. I think the 
following function will do what you want, although it is probably not 
the most elegant solution. I would check it manually with a small data 
file and a small "howmany" argument to make sure that it is picking up 
the maxima you want.

find.max.rain<-function(raindata,howmany) {
  # a lazy way of getting the same structure as raindata
  # it assumes that raindata has the data structure that you want
  maxrain<-raindata[1:howmany,]
  for(i in 1:howmany) {
   # get the current number of rows
   nrows<-dim(raindata)[1]
   # find the first maximum value
   thismax<-which.max(raindata$cumrain)
   # transfer it to the return data frame
   maxrain[i,]<-raindata[thismax,]
   # calculate the minimum index for the 48 hour gap
   mindex<-thismax-48
   # make sure it is at least 1
   if(mindex < 1) mindex <- 1
   # calculate the maximum index for the gap
   maxdex<-thismax+48
   # make sure it doesn't go past the end of the data frame
   if(maxdex > nrows) maxdex<-nrows
   # chop out that time period
   raindata<-raindata[-(mindex:maxdex),]
  }
  return(maxrain)
}

Jim