write.matrix(x, file = "", sep = " ", blocksize)"") is the console.blocksize rows.  Choose as large as possible consistent with
  the amount of memory available.x has them)
  and columns of data.x is a matrix, supplying blocksize is more
  memory-efficient and enables larger matrices to be written, but each
  block of rows might be formatted slightly differently.  If x is a data frame, the conversion to a matrix may negate the
  memory saving.
write.table