Merge by Range in R - Applying Loops

Question

I posted a question here: Matched Range Merge in R about merging two files based on a number in one file falling into a range in the second file. Thus far, I have been unsuc

Answer 1

You can merge by range in base by using apply and which. To return only those which match (inner join):

do.call(rbind, apply(file1test, 1, function(x) {
  if(length(idx <- which(x["BP"] >= file2$BP_start & x["BP"] <= file2$BP_end)) > 0) {
    cbind(rbind(x), file2[idx,])
  }
}))
#      SNP     BP  Gene BP_start BP_end
#x  rs2343 860269 E3543   860260 879955
#1   rs754 861822 E3543   860260 879955
#2   rs754 861822   E11   861322 879533
#x1  rs854 367934  E613   367640 368634

or all from file1test (left join):

do.call(rbind, apply(file1test, 1, function(x) {
  if(length(idx <- which(x["BP"] >= file2$BP_start & x["BP"] <= file2$BP_end)) > 0) {
    cbind(rbind(x), file2[idx,])
  } else {
    cbind(rbind(x), file2[1,][NA,])
  }
}))
#      SNP     BP  Gene BP_start BP_end
#x  rs2343 860269 E3543   860260 879955
#x1  rs211 369640         NA     NA
#1   rs754 861822 E3543   860260 879955
#2   rs754 861822   E11   861322 879533
#x2  rs854 367934  E613   367640 368634
#x3  rs343 706940         NA     NA
#x4  rs626 717244         NA     NA