I wonder how efficiently it is to do the following command on a frequent basis. nrow(matFF) <- nrow(matFF)+1
Obviously there is overhead (closing file, enlarging file, openeing file). I recommend you measure yourself whether this is acceptable for you.
no large file copying is needed each time the nrow is changed?
With a decent filesystem there is *no* copying from smaller to larger file.
would you think I can open 2000 large matrices and leave them open or I
need to close each after it is opened and used? Not tested yet. I guess the number of open files can be configured when compiling your OS. Please test and let us know your experience. Regards Jens Oehlschl?gel