transform count-data into binary coded data

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count1 <- count2 <- count3 <- count4 <- sample(c(rep(0, 10), 1:10)) some <- LETTERS[1:20]  thing <- letters[1:20]  mydf <- data.frame(count1, count2, count3, count4, some, thing) ids <- grep("count", names(mydf)) myfun <- function(x) {ifelse(x > 0, 1, 0)} mydf[, ids] <- lapply(mydf[, ids], myfun) http://thebiobucket.blogspot.com/2012/02/convert-several-variables-of-dataframe.html