Merging outbreak data

HI.
I have a set of disease outbreak data. Each observation have a
location (spatial coordinates) and a start date. Outbreaks that occur 

in

the same location within a two week periods have to be merged. 

Basically I

need to delete duplicates that have same spatial coordinated and 

start

dates comprised in a two weeks range. I am ok with the first bit
(coordinates), but It is the date range that I am not sure how to 

define. I

thought about creating a dummy variable for observations within a 

date

range, but those might have different locations. Any help would be 

greatly

appreciated. Thanks

Hi barbara,
I assume that the spatial coordinates have to be within a certain 
distance to be considered the same, unless they are based on 
something like cities or health administration districts. If your 
observations can be ordered by date, the problem is not too difficult.

date_range<-as.Date(c("1/1/2014","1/8/2014"),"%d/%m/%Y")
disease.df<-data.frame(
 onset=sample(seq(date_range[1],date_range[2],by=1),100),
 lat=sample(seq(-33,-35,by=-1),100,TRUE),
 lon=sample(seq(148,151,by=1),100,TRUE))
disease.df<-disease.df[order(disease.df$onset),]
disease.df$drop<-0
nobs<-dim(disease.df)[1]
for(start in 1:(nobs-1)) {
 cat(start,"\n")
 end<-start+1
 while(disease.df$onset[end] < disease.df$onset[start]+14 &&
  end < nobs) end<-end+1
 if(disease.df$onset[end] - disease.df$onset[start] > 14)
  end<-end-1
 sameplace<-
  disease.df$lat[start] == disease.df$lat[(start+1):end] &
  disease.df$lon[start] == disease.df$lon[(start+1):end]
 if(any(sameplace)) {
  disease.df$drop[start]<-1
  disease.df$drop[(start+1):end]<-
   disease.df$drop[(start+1):end]+sameplace
 }
}

Caution - I haven't checked this exhaustively and I have assumed that 
locations must be equal, not within some distance.

Jim