R help - Sep 2009 - How not to keep the redundant space when convert a data frame with as.matrix()?

Hi,

The first column in as.matrix(x) has extra spaces (" "), which I
don't
want. Is there a way not to generate those spaces?

Regards,
Peng
> x=data.frame(x=1:10,y=letters[11:20])
> as.matrix(x)
      x    y
 [1,] " 1" "k"
 [2,] " 2" "l"
 [3,] " 3" "m"
 [4,] " 4" "n"
 [5,] " 5" "o"
 [6,] " 6" "p"
 [7,] " 7" "q"
 [8,] " 8" "r"
 [9,] " 9" "s"
[10,] "10" "t"

> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of Peng Yu
> Sent: Wednesday, September 16, 2009 3:33 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] How not to keep the redundant space when convert 
> a data frame with as.matrix()?
> 
> Hi,
> 
> The first column in as.matrix(x) has extra spaces (" "), which I
don't
> want. Is there a way not to generate those spaces?
> 
> Regards,
> Peng
> 
> > x=data.frame(x=1:10,y=letters[11:20])
> > as.matrix(x)
>       x    y
>  [1,] " 1" "k"
>  [2,] " 2" "l"
>  [3,] " 3" "m"
>  [4,] " 4" "n"
>  [5,] " 5" "o"
>  [6,] " 6" "p"
>  [7,] " 7" "q"
>  [8,] " 8" "r"
>  [9,] " 9" "s"
> [10,] "10" "t"
> 
You have asked several questions about using as.matrix() on a data.frame
with colums of different types, in particular character and numeric types.
Since matrices can only have one type, your numerics are coerced to
character.  Is this what you really want?  Is there some reason you can't
use a data.frame?

Enquiring minds want to know?

Dan

Daniel Nordlund
Bothell, WA USA

If you want a matrix of strings

 > x <- data.frame(x=as.character(1:10),y=letters[11:20])
 > as.matrix(x)
       x    y
  [1,] "1"  "k"
  [2,] "2"  "l"
  [3,] "3"  "m"
  [4,] "4"  "n"
  [5,] "5"  "o"
  [6,] "6"  "p"
  [7,] "7"  "q"
  [8,] "8"  "r"
  [9,] "9"  "s"
[10,] "10" "t"

BTW I believe the "=" for assignments is discouraged.  Use
"<-".

>> x=data.frame(x=as.character(1:10),y=letters[11:20])
>> as.matrix(x)

On 16-Sep-09, at 3:33 PM, Peng Yu wrote:
> Hi,
>
> The first column in as.matrix(x) has extra spaces (" "), which I
don't
> want. Is there a way not to generate those spaces?
>
> Regards,
> Peng
>
>> x=data.frame(x=1:10,y=letters[11:20])
>> as.matrix(x)
>       x    y
>  [1,] " 1" "k"
>  [2,] " 2" "l"
>  [3,] " 3" "m"
>  [4,] " 4" "n"
>  [5,] " 5" "o"
>  [6,] " 6" "p"
>  [7,] " 7" "q"
>  [8,] " 8" "r"
>  [9,] " 9" "s"
> [10,] "10" "t"
>
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