splitting and reorganising a data.frame

x

xtabs(height ~ Seed + age, x)

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


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