[R] Dataframe modification

[Gabor Grothendieck]

Ramzi Feghali <ramzi_feg <at> yahoo.fr> writes:

: 
: Hello,
: I have a problem and wish if anybody have a quick
: solution or function or if this question was asked
: before and you could give me the date to look in the
: archives for the response.
: My problem is that I have a dataframe D[663,40] with
: only  one column with repeated values lines and a
: factor with 4 levels.
: I want to reorganize my dataframe, create a dataframe
: D1[x,40*4] and put the repeated values in one line so
: that all the factors will be in columns. For the
: values with a missing level factor I want to keep
: empty the concerning place.
: For example if i a have this dataframe:
: 
: A	B	C							
	
: 32	a	14							
	
: 32	b	22							
	
: 55	a	44							
	
: 55	b	77							
	
: 55	c	55							
	
: 55	d	44							
	
: 83	c	77							
	
: 83	d	55							
	
: 83	e	44						
: I want to transform it to have this one: 
: 
: 32	a	14	b	22					
	
: 55	a	44	b	77	c	55			
	
: 83					c	77	d	55	e
	44
: 



Is this good enough?

R> # first solution
R> reshape(D, idvar="A", timevar="B", direction = "wide")
   A C.a C.b C.c C.d C.e
1 32  14  22  NA  NA  NA
3 55  44  77  55  44  NA
7 83  NA  NA  77  55  44

R> # second solution
R> xtabs(C ~ A + B, D)
    B
A     a  b  c  d  e
  32 14 22  0  0  0
  55 44 77 55 44  0
  83  0  0 77 55 44