How can I add rows to an R data frame every other row?

Question

Brief: how can I add m rows to my m X n data frame, where each new row is inserted after each existing row? I will essentially copy the existing ro

Answer 1

modified from "e4e5f4's" response

Insert blank rows betweens rows

    # sample matrix of df 
    old <-matrix(1:9, ncol=3)

    # double all rows 
    new <- old[rep(1:nrow(old),1,each=2),]

    # replace all duplicates with blank cells
    new[c(seq(2, dim(new)[1], by=2)), ] <- ""

    old # original 
    new # all ok ;)