[R] unique sets of factors

Gabor Grothendieck ggrothendieck at gmail.com
Fri Oct 20 01:22:07 CEST 2006


Or since that messes up the values:

u <- unique(t(apply(DF, 1, function(x) as.numeric(factor(x, levels =
unique(x))))))
DF[rownames(u), ]


On 10/19/06, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> If DF is a data frame containing the rows then:
>
> unique(t(apply(DF, 1, function(x) as.numeric(factor(x, levels = unique(x))))))
>
>
> On 10/19/06, Tony Long <tdlong at uci.edu> wrote:
> > All:
> >
> > I have a matrix, X, with a LARGE number of rows.  Consider the
> > following three rows of that matrix:
> >
> > 1 1 1 1 2 2 3 3
> > 1 1 1 1 3 3 2 2
> > 3 3 2 2 1 1 1 1
> >
> > I wish to fit many one-way ANOVAs to some response variable using
> > each row as a set of factors.  For example, for each row above I will
> > do something like anova(lm(Y~as.factor(X[1,]))).  My problem is that
> > in the above example, I do not want to fit models for both rows 1 and
> > 2 as they are essentially duplicates in terms of the ANOVA model.
> > Clearly row 3, although it has the same number of 1's, 2's, and 3's,
> > is a different model.
> >
> > Is there some computationally efficient way to remove such "factor
> > duplicates" from my large matrix?  I have been banging my head
> > against the wall all morning.
> >
> > Thanks!!
> >
> > Tony
> > --
> > ###########################
> >
> > Tony Long
> >
> > Ecology and Evolutionary Biology
> > Steinhaus Hall
> > University of California at Irvine
> > Irvine, CA
> > 92697-2525
> >
> > Tel:  (949) 824-2562   (office)
> > Tel:  (949) 824-5994   (lab)
> > Fax: (949) 824-2181
> >
> > email:  tdlong at uci.edu
> > http://hjmuller.bio.uci.edu/~labhome/
> >
> > ______________________________________________
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> > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>



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