[R] as.matrix and one row

[Peter Dalgaard]

Federico Calboli <f.calboli at imperial.ac.uk> writes:

> Hi All,
> 
> I have the following problem:
> 
> x = c(1,2)
> x
> [1] 1 2
> 
> as.matrix(x)
>      [,1]
> [1,]    1
> [2,]    2
> 
> BUT, if I add:
> 
> y = c(3,4)
> 
> as.matrix(rbind(x,y))
>   [,1] [,2]
> x    1    2
> y    3    4
> 
> It does not transpose. Since I will need as.matrix() for a list of data
> that is in one or more lines, I need as.matrix to behave in a consisten
> fashions, so I get 

Well, it's a NOP since the argument is a matrix already. R is not
"transposing" in the first case either, since the argument is not a
matrix. However, the convention is that vectors are treated as column
vectors, even though they print horisontally. 

rbind(x) should get you to where you want soon enough.
 
> as.matrix(x, whatever)
>   [,1] [,2]
> x    1    2
> 
> and 
> 
> as.matrix(rbind(x,y), whatever)
>   [,1] [,2]
> x    1    2
> y    3    4
> 
> I tried byrow =T, does not make a thing.
> 
> Regards,
> 
> Federico Calboli
> 
> -- 
> Federico C. F. Calboli
> Department of Epidemiology and Public Health
> Imperial College, St Mary's Campus
> Norfolk Place, London W2 1PG
> 
> Tel  +44 (0)20 7594 1602     Fax (+44) 020 7594 3193
> 
> f.calboli [.a.t] imperial.ac.uk
> f.calboli [.a.t] gmail.com
> 
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-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907