[R] fractional factorial design in R
gunter.berton at gene.com
Mon Jan 23 20:28:45 CET 2006
> At the moment, I am using an SPSS function (orthoplan) for my
> needs. It provides factorial design with only main effects
> (small orthogonal designs).
> Since SPSS is very expensive (in particular with this
> add-on), I would like to use R as for all my other projects
> and research activity.
Yes, you're right. For, say, a 3 x 5 design, one can do this in as few as 7
runs -- but only in general by some version of one-factor-at-a-time (OFAT)
designs, which are inefficient. It is easy, via, say model.matrix() to
write a general function to produce these. But I think it's a bad idea; more
efiicient algorithmic designs are better, IMO, which is why I suggested
AlgDesign. You and others are free to disagree, of course.
> Do you know any other way to produce these designs in R?
> Thanks in advance,
> Roberto Furlan
> University of Turin, Italy
> La mia Cartella di Posta in Arrivo è protetta con SPAMfighter
> 188 messaggi contenenti spam sono stati bloccati con successo.
> Scarica gratuitamente SPAMfighter!
More information about the R-help