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

[arun]

Hi,
I guess you are not talking about the melt() method.
dat1<-read.table(text="
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
",header=TRUE,sep="",stringsAsFactors=FALSE)


#If all the Sp columns are located next to another as shown in your example dataset, then you can also try this:
name1<-unlist(strsplit(paste(colnames(dat1)[4:6],collapse=" ")," "))
reshape(dat1,varying=4:6,v.name="Sp-value",times=name1,timevar="Sp-name",idvar=c("Year","Route","Point"),direction="long")

A.K.






----- Original Message -----
From: Rui Barradas <ruipbarradas at sapo.pt>
To: agoijman <agoijman at cnia.inta.gov.ar>
Cc: r-help at r-project.org
Sent: Sunday, October 7, 2012 2:32 PM
Subject: Re: [R] Presence/ absence data from matrix to single column

Hello,

I haven't been following this thread but apparently the answer to your 
worries is no.
You can use a combination of names() and grep() to sort it out. 
something like

#nms <- names(adat)
nms <- c("Year", "Route", "Point", paste0("Sp", 1:250))

pattern <- "^Sp[[:digit:]]+$"
whichCols <- grep(pattern, nms)
whichNames <- nms[whichCols]

reshape(..., varying = whichCols, times = whichNames, ...)


Hope this helps,

Rui Barradas
Em 07-10-2012 15:35, agoijman escreveu:
> 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-column-tp4645271p4645331.html
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