R help - Apr 2011 - splitting and reorganising a data.frame

Hey,

i have a question about how to reorganize a data frame in the easiest way.

my example:  what would be the easiest way to bring a data.frame such like this:

----
   nr height age Seed
1   1   4.51   3  301
2  15  10.89   5  301
3  29  28.72  10  301
4  43  41.74  15  301
5  57  52.70  20  301
6  71  60.92  25  301
7   2   4.55   3  303
8  16  10.92   5  303
9  30  29.07  10  303
10 44  42.83  15  303
11 58  53.88  20  303
12 72  63.39  25  303
13  3   4.79   3  305
14 17  11.37   5  305
15 31  30.21  10  305
16 45  44.40  15  305
17 59  55.82  20  305
18 73  64.10  25  305

----- (the loblolly data)

into this form:

----
      3     5    10    15    20    25
301 4.51 10.89 28.72 41.74 52.70 60.92
303 4.55 10.92 29.07 42.83 53.88 63.39
305 4.79 11.37 30.21 44.40 55.82 64.10
--- 
the columns contain the height for each age level and the row the seed level


right now im doing it like this:

groups <- split(data,Seed)
data2 <- data.frame()
for (group in groups)
{
  row <- data.frame(t(group[,2]))
  colnames(row) <- group$age
  rownames(row) <- group$Seed[1]
  data2 <- rbind(data2,row) 
}

but isnt there any nicer way? i need to teach some people how to do this, and i
think this solution might be a bit confusing for the start.

Thanks a lot,
Lutz


	[[alternative HTML version deleted]]

try this:
> x
   nr height age Seed
1   1   4.51   3  301
2  15  10.89   5  301
3  29  28.72  10  301
4  43  41.74  15  301
5  57  52.70  20  301
6  71  60.92  25  301
7   2   4.55   3  303
8  16  10.92   5  303
9  30  29.07  10  303
10 44  42.83  15  303
11 58  53.88  20  303
12 72  63.39  25  303
13  3   4.79   3  305
14 17  11.37   5  305
15 31  30.21  10  305
16 45  44.40  15  305
17 59  55.82  20  305
18 73  64.10  25  305
> xtabs(height ~ Seed + age, x)
     age
Seed      3     5    10    15    20    25
  301  4.51 10.89 28.72 41.74 52.70 60.92
  303  4.55 10.92 29.07 42.83 53.88 63.39
  305  4.79 11.37 30.21 44.40 55.82 64.10
>

On Tue, Apr 26, 2011 at 10:57 AM, Lutze <lutzeputze at googlemail.com>
wrote:
> Hey,
>
> i have a question about how to reorganize a data frame in the easiest way.
>
> my example: ?what would be the easiest way to bring a data.frame such like
this:
>
> ----
> ? nr height age Seed
> 1 ? 1 ? 4.51 ? 3 ?301
> 2 ?15 ?10.89 ? 5 ?301
> 3 ?29 ?28.72 ?10 ?301
> 4 ?43 ?41.74 ?15 ?301
> 5 ?57 ?52.70 ?20 ?301
> 6 ?71 ?60.92 ?25 ?301
> 7 ? 2 ? 4.55 ? 3 ?303
> 8 ?16 ?10.92 ? 5 ?303
> 9 ?30 ?29.07 ?10 ?303
> 10 44 ?42.83 ?15 ?303
> 11 58 ?53.88 ?20 ?303
> 12 72 ?63.39 ?25 ?303
> 13 ?3 ? 4.79 ? 3 ?305
> 14 17 ?11.37 ? 5 ?305
> 15 31 ?30.21 ?10 ?305
> 16 45 ?44.40 ?15 ?305
> 17 59 ?55.82 ?20 ?305
> 18 73 ?64.10 ?25 ?305
>
> ----- (the loblolly data)
>
> into this form:
>
> ----
> ? ? ?3 ? ? 5 ? ?10 ? ?15 ? ?20 ? ?25
> 301 4.51 10.89 28.72 41.74 52.70 60.92
> 303 4.55 10.92 29.07 42.83 53.88 63.39
> 305 4.79 11.37 30.21 44.40 55.82 64.10
> ---
> the columns contain the height for each age level and the row the seed
level
>
>
> right now im doing it like this:
>
> groups <- split(data,Seed)
> data2 <- data.frame()
> for (group in groups)
> {
> ?row <- data.frame(t(group[,2]))
> ?colnames(row) <- group$age
> ?rownames(row) <- group$Seed[1]
> ?data2 <- rbind(data2,row)
> }
>
> but isnt there any nicer way? i need to teach some people how to do this,
and i think this solution might be a bit confusing for the start.
>
> Thanks a lot,
> Lutz
>
>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?