Re: [R] Explanation w.r.t. rbind, please!
Meyners,Michael,LAUSANNE,AppliedMathematics wrote: What you (probably) want here is num.mat ["seq",] > num.mat [num.vec] [1] NA NA NA NA num.mat["num.vec",] and so on. You have to use tell R that you want the ROW (that's why the comma is needed) defined by the NAME "seq" or "num.vec" (that's why you need "") . Thanks, I had been exactly there before, and it didn't work neither. Now it works. I do understand the need for the rows *now*. Uwe __ R-help@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.
Re: [R] Explanation w.r.t. rbind, please!
> -Original Message-
> From: r-help-boun...@r-project.org
> [mailto:r-help-boun...@r-project.org] On Behalf Of Uwe Dippel
> Sent: Freitag, 29. Januar 2010 11:57
> To: r-help@r-project.org
> Subject: [R] Explanation w.r.t. rbind, please!
>
> This is what I tried:
>
> > num.vec <- c(12.34,56.78,90.12,34.56) >
> names(num.vec)<-c("first","second","third","fourth")
> > num.vec
> first second third fourth
> 12.34 56.78 90.12 34.56
> > seq<-(1:4)
> > num.mat<-rbind(num.vec,seq)
> > num.mat
> first second third fourth
> num.vec 12.34 56.78 90.12 34.56
> seq 1.00 2.00 3.00 4.00
> > num.vec [3:4]
> third fourth
> 90.12 34.56
>
> (until here I'm fine)
>
> > num.mat [seq]
> [1] 12.34 1.00 56.78 2.00
What you (probably) want here is
num.mat ["seq",]
> > num.mat [num.vec]
> [1] NA NA NA NA
num.mat["num.vec",]
and so on. You have to use tell R that you want the ROW (that's why the
comma is needed) defined by the NAME "seq" or "num.vec" (that's why you
need "") . Otherwise, R replaces seq by its value 1:4, so
num.mat[seq]
is identical to
num.mat[1:4]
(and num.mat[12.34] is NA of course in num.mat[num.vec])
You should have a closer look at ?Extract
HTH, Michael
> > num.vec [seq]
> first second third fourth
> 12.34 56.78 90.12 34.56
> > num.mat [num.vec]
> [1] NA NA NA NA
> > num.mat [-seq]
> [1] 90.12 3.00 34.56 4.00
>
> (and here I'm lost!)
>
> How could I display a row, instead of always seemingly
> falling back to columns?
>
> Uwe
>
> __
> R-help@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@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.
Re: [R] Explanation w.r.t. rbind, please!
On Fri, 2010-01-29 at 18:56 +0800, Uwe Dippel wrote:
> This is what I tried:
>
> > num.vec <- c(12.34,56.78,90.12,34.56)
> > names(num.vec)<-c("first","second","third","fourth")
> > num.vec
> first second third fourth
> 12.34 56.78 90.12 34.56
> > seq<-(1:4)
> > num.mat<-rbind(num.vec,seq)
> > num.mat
> first second third fourth
> num.vec 12.34 56.78 90.12 34.56
> seq 1.00 2.00 3.00 4.00
> > num.vec [3:4]
> third fourth
> 90.12 34.56
>
> (until here I'm fine)
>
> > num.mat [seq]
> [1] 12.34 1.00 56.78 2.00
> > num.mat [num.vec]
> [1] NA NA NA NA
> > num.vec [seq]
> first second third fourth
> 12.34 56.78 90.12 34.56
> > num.mat [num.vec]
> [1] NA NA NA NA
> > num.mat [-seq]
> [1] 90.12 3.00 34.56 4.00
>
> (and here I'm lost!)
>
> How could I display a row, instead of always seemingly falling back to
> columns?
You're indexing the matrix as if it were a vector. Which is fine, except
that in R matrices are indexed by columns, hence the last result your
got - you dropped the first 4 entries which are the first two columns,
hence you got the last two columns of data.
Knowing this you could alter your seq to be seq(1, 8, by = 2):
> num.mat[seq(1, 8, by = 2)]
[1] 12.34 56.78 90.12 34.56
Thank full there is an easier way:
?`[`
has the details, look at arguments i and j.
> num.mat[1,]
first second third fourth
12.34 56.78 90.12 34.56
or, without the (col)names
> unname(num.mat[1,])
[1] 12.34 56.78 90.12 34.56
HTH
G
>
> Uwe
>
> __
> R-help@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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Dr. Gavin Simpson [t] +44 (0)20 7679 0522
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__
R-help@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] Explanation w.r.t. rbind, please!
This is what I tried:
> num.vec <- c(12.34,56.78,90.12,34.56)
> names(num.vec)<-c("first","second","third","fourth")
> num.vec
first second third fourth
12.34 56.78 90.12 34.56
> seq<-(1:4)
> num.mat<-rbind(num.vec,seq)
> num.mat
first second third fourth
num.vec 12.34 56.78 90.12 34.56
seq 1.00 2.00 3.00 4.00
> num.vec [3:4]
third fourth
90.12 34.56
(until here I'm fine)
> num.mat [seq]
[1] 12.34 1.00 56.78 2.00
> num.mat [num.vec]
[1] NA NA NA NA
> num.vec [seq]
first second third fourth
12.34 56.78 90.12 34.56
> num.mat [num.vec]
[1] NA NA NA NA
> num.mat [-seq]
[1] 90.12 3.00 34.56 4.00
(and here I'm lost!)
How could I display a row, instead of always seemingly falling back to
columns?
Uwe
__
R-help@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.
