R transforming multiple rows into columns

Question

Hi all I have a table

id  sample_name replicates  raw 
a   control     c1          1   
a   control     c2          2   
a   control     c3          3   
b   control     c1          10    
b   control     c2          20   
b   control     c3          20

and would like to transform this to

id c1   c2   c3 
a  1    2    3    
b  10   20   20

The only way I know how to do this is to brute loop through every 3, because there are 3 replicates and append that to multiple vectors and recombine it at the end into a dataframe, thus I'm wondering if there is a more elegant/simple way to do this? thanks!

Your data is in "long" form - you want it in "wide" form. Search the R tag for "long to wide" and you will find many examples, especially using `reshape2::dcast` or `tidyr::spread`. — Gregor Thomas, Apr 13 '16 at 22:12
@alistaire thanks! exactly what I need. Sorry for the redundancy. — Ahdee, Apr 13 '16 at 22:29

score 1 · Answer 1 · answered Apr 13 '16 at 22:14

1

Try this...

> library(reshape2)
> dcast(melt(df[, -2]), ...~replicates)[, -2]
Using id, replicates as id variables
  id c1 c2 c3
1  a  1  2  3
2  b 10 20 20

answered Apr 13 '16 at 22:14

Jilber Urbina

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R transforming multiple rows into columns

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