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

Your sample data:

orig.df <- read.table(text = "
Label easting northing elevation length
47063  554952  5804714 32.68 619.25 
47311  492126  5730703 10.40 1773.00", header = TRUE)

Create your data to be inserted:

insert.df <- transform(orig.df, elevation = elevation - length)

Append it to your original data:

out.df <- rbind(orig.df, insert.df)

Reorder the rows:

n <- nrow(orig.df)
out.df[kronecker(1:n, c(0, n), "+"), ]
#   Label easting northing elevation  length
# 1 47063  554952  5804714     32.68  619.25
# 3 47063  554952  5804714   -586.57  619.25
# 2 47311  492126  5730703     10.40 1773.00
# 4 47311  492126  5730703  -1762.60 1773.00