Re: [R] Converting a data frame with values into a matrix/

From: John Kane <jrkrideau_at_yahoo.ca>
Date: Wed, 12 Mar 2008 14:21:54 -0400 (EDT)


Oops, I just realised that you asked for a matrix not a data.frame Substituing for the last three lines of code

final <- as.matrix(aba)
colnames(final) <- aa$Name
rownames(final) <- mm1$Class

should do it.
--- John Kane <jrkrideau_at_yahoo.ca> wrote:

> The way that you have set up the data.frame is
> rather
> unusual. It makes NES a factor which I suspect you
> don't want. Do str(xx) to see what I mean
>
> Here is a way that I think does what you want but
> with
> the data.frame constructed in a different manner.
> Again do str(aa) to see the difference
>



> aa <- data.frame(Name=c( "Mike" ,"Carl", "Gene",
> "James","Dough"),
> Class=c( "A", "A", "C", "A", "B"),
> NES=c( 0.01, 0.2, 0.3, -0.3, 0) )
> aa
>
> library(reshape)
> mm <- melt(aa, id=c("Name", "Class"))
> mm1 <- cast(mm, Class~Name)
>
> aba <- mm1[,2:6]
> aba[is.na(aba)] <- 1
>
> final <- data.frame(mm1$Class, aba)
> names(final) <- names(mm1)
> final
>
> ===================================================
>
> --- Srinivas Iyyer <srini_iyyer_bio_at_yahoo.com>
> wrote:
>
> > Dear Group,
> > I have a data frame like the following:
> >
> >
> > x <- c("Mike","A",0.01)
> > x1 <- c("Carl","A",0.2)
> > x2 <- c("Gene","C",0.3)
> > x3 <- c("James","A",-0.3)
> > x4 <- c("Dough","B",0)
> > xx <- rbind(x,x1,x2,x3,x4)
> > colnames(xx)<-c("Name","Class","NES")
> > xx <-as.data.frame(xx)
> >
> > > xx
> > Name Class NES
> > x Mike A 0.01
> > x1 Carl A 0.2
> > x2 Gene C 0.3
> > x3 James A -0.3
> > x4 Dough B 0
> >
> >
> > Now I want to create a matrix with unique xx$Name
> on
> > columns and unique xx$Class as rows. I want to
> fill
> > my choice of values (in this case 1) if data point
> > not
> > available.
> >
> >
> > xy <-
> >
>
matrix(1,length(unique(xx$Class)),length(unique(xx[,1])))
> > colnames(xy)<-unique(xx[,1])
> > rownames(xy)<-unique(xx$Class)
> >
> > > xy
> > Mike Carl Gene James Dough
> > A 1 1 1 1 1
> > C 1 1 1 1 1
> > B 1 1 1 1 1
> >
> >
> >
> >
> >
> > I would love to have :
> >
> > Mike Carl Gene James Dough
> > A 0.01 0.2 1 -0.3 1
> > C 1 1 1 0.3 1
> > B 1 1 1 1 0
> >
> >
> >
> >
> > If I am not wrong this is called contigency or
> > frequeny table.
> >
> > I tried xtabs on this.
> >
> > > z <- xtabs(NES ~ Name+Class,data=xx)
> > Error in Summary.factor(4L, na.rm = FALSE) :
> > sum not meaningful for factors
> >
> >
> > I tried on other data frames, it worked. BUT the
> > problem is it gives me 0.0000 even a value is not
> > available for that row and column. So if I have
> > data
> > -0.00 it is considered 0.
> >
> > I tried. drop.unused.levels = T, I did not get
> what
> > I
> > want. I want all row.col values not available to
> be
> > 1.
> >
> >
> > Is there any other trick where I map by row and
> > column
> > names instead of using advanced xtabs.
> >
> > thanks
> > Srini
> >
> > ______________________________________________
> > 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.
> >
>
> ______________________________________________
> 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.
>

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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. Received on Wed 12 Mar 2008 - 18:28:35 GMT

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