Hi, Try: library(stringr) res <- transform(dat[rep(1:nrow(dat),str_count(dat$Result,"-")+1),],Result=unlist(strsplit(as.character(dat$Result)," - ")),Batch=ave(Batch,Batch,FUN=function(x) paste0(x,letters[seq_along(x)]))) ?row.names(res) <- 1:nrow(res) # Based on the expected results, it could be also: res1 <-? transform(dat[rep(1:nrow(dat),str_count(dat$Result,"-")+1),],Result=unlist(strsplit(as.character(dat$Result)," - ")),Batch=ave(Batch,Batch,Test,FUN=function(x) paste0(x,letters[seq_along(x)]))) ?row.names(res1) <- 1:nrow(res1) A.K. Hi, I have a dataframe with some data from experiments: Batch ? Test ?Result ? ? ? ?LL ? ? ? ?......(many more columns, all the same within Batch/Test) ? 1 ? ? ? ? A ? ? 6,5-6,7 ? ? 6,00 ? ?..... ? 1 ? ? ? ? B ? ? 95,1-95,3 ?95,00 ?..... ? 2 ? ? ? ? A ? ? 6,5-6,7 ? ? 6,00 ? ?..... ... Some results have double values, instead of 1 single numeric value, all separated by "-". But now I want a dataframe with only 1 value per Batch/Test, and batches with double values should be renamed to 1a, 1b, ... So Batch ? Test ?Result ? ? ? ?LL ? ? ? ?......(many more columns, all the same within Batch/Test) ? 1a ? ? ? ?A ? ? 6,5 ? 1b ? ? ? ?A ? ? 6,7 ? ? 6,00 ? ?..... ? 1a ? ? ? ?B ? ? 95,1 ?95,00 ?..... ? 1b ? ? ? ?B ? ? 95,3 ?95,00 ?..... ? 2a ? ? ? ?A ? ? 6,5 ? ? 6,00 ? ?..... ? 2b ? ? ? ?A ? ? 6,7 ? ? 6,00 ? ?..... ... I tried with by and strsplit, but couldn't figure it out. Any help would be appreciated, example data below. Bart dat <- structure(list(Batch = c(1L, 1L, 2L, 2L, 3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L), Test = structure(c(1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 2L, 2L), .Label = c("A", "B"), class = "factor"), Result = structure(c(12L, 4L, 8L, 6L, 11L, 5L, 10L, 2L, 9L, 3L, 1L, 7L), .Label = c("6,604 - 6,59 - 6,585 - 6,588", "6,61", "6,625 - 6,607", "6,675", "6,71 - 6,74", "6,76 - 6,75", "6,79 - 6,80", "98,28 - 99,14", "98,52", "99,05 - 99,15", "99,74 - 98,19", "99,77 - 99,62"), class = "factor"), X = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA), LL = structure(c(2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 1L, 1L), .Label = c("6,00", "95"), class = "factor")), .Names = c("Batch", "Test", "Result", "X", "LL"), class = "data.frame", row.names = c(NA, -12L))