search for: _fractional_

Hi all, Does anybody know if it is possible to build a fractional factorial design in R? That is, suppose that we want do design an experiment with 3 factors with 2, 3 and 3 levels, respectivly. However we want to consider, let's say, only 6 from all possible level combinations. Does R design such experiment? Thanks in advance, Caio [[alternative HTML version deleted]]

I am wondering if there is a good way to work with data that is indexed in time, via timestamps with a resolution in milliseconds. As I understand it, the POSIX classes have a resolution i n terms of seconds, and will not process fractional seconds from a string. Is this correct. I realize that this may be a little unclear. Here is what I am trying to do: A data frame with a time series