[R] Filling data frame data into a matrix - please help

[Henrique Dallazuanna]

Perhaps this helps:

myres <- d1.tb[]
attributes(myres)$call <- NULL
myres
class(myres)

If you want remove 'c1' and 'r1' then:
names(dimnames(myres)) <- NULL
class(myres)






On 24/01/2008, Srinivas Iyyer <srini_iyyer_bio at yahoo.com> wrote:
> Dear Henrique,
> thanks for the tip.
>
> One question though: how do I get back a matrix out of
> d1.tb.
> d1.tb is an xtabs object.
>
> I tried:
>
> myres <- ftable(d1.tb)
> myre1 <- as.data.frame(myres)
>
> now myres1 is nor a matrix or a df.
>
> I want d1.tb as a matrix.
>
> Please suggest.
>
> thanks
> srini
>
> --- Henrique Dallazuanna <wwwhsd at gmail.com> wrote:
>
> > Try this:
> >
> > d1 <- data.frame(d1)
> > d1$V3 <- as.numeric(as.character(d1$V3))
> > xtabs(V3 ~ r1+c1, data=d1)
> >
> > You can substitute 0 with NA:
> >
> > d1.tb <- xtabs(V3 ~ r1+c1, data=d1)
> > d1.tb[d1.tb==0] <- NA
> >
> >
> > On 24/01/2008, Srinivas Iyyer
> > <srini_iyyer_bio at yahoo.com> wrote:
> > > Dear group,
> > > I have a data.frame (d1) with various elements and
> > a
> > > matrix (m1) created with NA (or 1s). I want to
> > read
> > > each row,column in d1 and fill its numeric value
> > in
> > > m1.
> > >
> > > Could some one help me because I have 130K rows
> > and
> > > 500 column data.frame object and I was told that a
> > for
> > > loop will take a long time.
> > >
> > > Thank you.
> > >
> > > > r1 <- c("A","A","B","B")
> > > > c1 <- c("Apple","Andy","Boy","Ball")
> > > > v1 <- as.numeric(c(0.001,0.02,0.3,NA))
> > > > d1 <- cbind(r1,c1,as.numeric(v1))
> > > > d1 <- data.frame(d1)
> > > > d1
> > >   r1    c1    V3
> > > 1  A Apple 0.001
> > > 2  A  Andy  0.02
> > > 3  B   Boy   0.3
> > > 4  B  Ball  <NA>
> > >
> > >
> > > > m1 <- matrix(NA,2,4)
> > > > rownames(m1)<- unique(r1)
> > > > colnames(m1)<-unique(c1)
> > > > m1
> > >   Apple Andy Boy Ball
> > > A    NA   NA  NA   NA
> > > B    NA   NA  NA   NA
> > >
> > >
> > > I want to have:
> > >
> > > result:
> > >
> > >
> > >   Apple   Andy  Boy  Ball
> > > A 0.001   0.02  NA    NA
> > > B  NA     NA    0.3   NA
> > >
> > >
> > > thanks
> > > Srini
> > >
> > >
> > >
> >
> ____________________________________________________________________________________
> > > Be a better friend, newshound, and
> > >
> > > ______________________________________________
> > > R-help at r-project.org mailing list
> > > 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.
> > >
> >
> >
> > --
> > Henrique Dallazuanna
> > Curitiba-Paraná-Brasil
> > 25° 25' 40" S 49° 16' 22" O
> >
>
>
>
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-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O