[R] Presence/ absence data from matrix to single column

[David L Carlson]

You should keep the context of your thread intact for those of us using
email instead of Nabble.

The locations were not listed individually anywhere in the reshape()
command. I listed Point as the id variable so reshape would use that to
create row names, but if you delete idvar="Point", reshape will give each
row a consecutive number followed by the species name or number.

I did list the species names individually in the times= argument to make
things a bit clearer since reshape() can be a confusing command at first.
But this would work as well:

reshape(adat, varying=4:6, v.name="Sp-value", 
  times=names(adat)[4:6], idvar="Point", 
  timevar="Sp-name", direction="long")

----------------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77843-4352

> Date: Sun, 7 Oct 2012 07:35:42 -0700 (PDT)
> From: agoijman <agoijman at cnia.inta.gov.ar>
> To: r-help at r-project.org
> Subject: Re: [R] Presence/ absence data from matrix to single column
> 
> 
> The problem with that, is that I just wrote an example of my database, but
I
> have around 250 species and more than 500 sites. In the approach you show
> me, it looks like I have to enter every species name and sites
individually,
> right?
> 
> 
> --
> View this message in context:
http://r.789695.n4.nabble.com/Presence-absence-data-from-matrix-to-single-co
lumn-tp4645271p4645331.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> _____________________________________________
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> PLEASE do read the posting guide
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> > -----Original Message-----
> > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> > project.org] On Behalf Of David L Carlson
> > Sent: Saturday, October 06, 2012 10:25 PM
> > To: 'Jim Lemon'; 'agoijman'
> > Cc: r-help at r-project.org
> > Subject: Re: [R] Presence/ absence data from matrix to single column
> > 
> > Also reshape() will work:
> > 
> > adat<-data.frame(Year=rep(2004,3),Route=rep(123,3),
> >   Point=c("123-1","123-2","123-10"),Sp1=c(0,0,1),
> >   Sp2=c(1,1,1),Sp3=c(0,1,0))
> > reshape(adat, varying=4:6, v.name="Sp-value",
> >   times=c("Sp1", "Sp2", "Sp3"), idvar="Point",
> >   timevar="Sp-name", direction="long")
> > 
> > ----------------------------------------------
> > David L Carlson
> > Associate Professor of Anthropology
> > Texas A&M University
> > College Station, TX 77843-4352
> > 
> > 
> > > -----Original Message-----
> > > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> > > project.org] On Behalf Of Jim Lemon
> > > Sent: Saturday, October 06, 2012 7:36 PM
> > > To: agoijman
> > > Cc: r-help at r-project.org
> > > Subject: Re: [R] Presence/ absence data from matrix to single column
> > >
> > > On 10/07/2012 01:03 AM, agoijman wrote:
> > > > I've been trying to reshape this database but haven't succeed at
> > it.
> > > I tried
> > > > using loops but can't get it right. I just want to reshape my
> > > database from
> > > > this matrix, to the one below, with only one column of data.
> > > >
> > > > Year	Route	Point	Sp1	Sp2	Sp3
> > > > 2004	123	123-1	0	1	0
> > > > 2004	123	123-2	0	1	1
> > > > 2004	123	123-10	1	1	0
> > > >
> > > > What I want:
> > > >
> > > > Year	Route	Point
> > > > 2004	123	123-1	Sp1	0
> > > > 2004	123	123-2	Sp1	0
> > > > 2004	123	123-10	Sp1	1
> > > > 2004	123	123-1	Sp2	1
> > > > 2004	123	123-2	Sp2	1
> > > > 2004	123	123-10	Sp2	1
> > > > 2004	123	123-1	Sp3	0
> > > > 2004	123	123-2	Sp3	1
> > > > 2004	123	123-10	Sp3	0
> > > >
> > > >
> > > Hi agoijman,
> > > You can do this using the rep_n_stack function.
> > >
> > > adat<-data.frame(Year=rep(2004,3),Route=rep(123,3),
> > >   Point=c("123-1","123-2","123-10"),Sp1=c(0,0,1),
> > >   Sp2=c(1,1,1),Sp3=c(0,1,0))
> > > library(prettyR)
> > > rep_n_stack(adat,c("Sp1","Sp2","Sp3"),
> > >   stack.names=c("Sp-names","Sp-values"))
> > >
> > > Jim
> > >
> > > ______________________________________________
> > > 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.
>