You really really need to go through one of the many R (web) tutorials where this is discussed in detail. Or see the Intro to R tutorial that ships with R. This is not the proper venue for learning how R handles linear models and how its formula interface works. A terse treatment can be found in ?lm, ?aov, and ?formula and links therein, but a suitable tutorial would probably be a better alternative.
Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Sun, Jun 25, 2017 at 10:05 PM, Jinsong Zhao <jsz...@yeah.net> wrote: > Hi there, > > I have a experimental design related question. I have done a experiment with > 3 factors. The design matrix is similar to: > >> data.frame(Factor.1 = rep(rep(0:2, each = 3),3), Factor.2 = > > rep(c("U","S","N"), 9), Factor.3 = rep(0:2, each = 9)) > Factor.1 Factor.2 Factor.3 > 1 0 U 0 > 2 0 S 0 > 3 0 N 0 > 4 1 U 0 > 5 1 S 0 > 6 1 N 0 > 7 2 U 0 > 8 2 S 0 > 9 2 N 0 > 10 0 U 1 > 11 0 S 1 > 12 0 N 1 > 13 1 U 1 > 14 1 S 1 > 15 1 N 1 > 16 2 U 1 > 17 2 S 1 > 18 2 N 1 > 19 0 U 2 > 20 0 S 2 > 21 0 N 2 > 22 1 U 2 > 23 1 S 2 > 24 1 N 2 > 25 2 U 2 > 26 2 S 2 > 27 2 N 2 > > The Factor.2 indicates the type of a fertilizer, such as urea, and the > Factor.3 indicates the weight of the fertilizer. So the treatments with > Factor.3 == 0 at each levels of Factor.1 are same. That means No.1, No.2 and > No.3 are same, No.4, No.5 and No.6 are same, and No.7, No.8 and No.9 are > same. Thus, in the real experiment, those treatments were not performed as > stated in the design matrix. For instance, only No.1, No.5 and No.9 are > performed. > > In the case, how to code the factor for ANOVA? I really appreciate any > comments and suggestions. Thanks in advance. > > Best regards, > Jinsong > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.