[R] Struchture change of a data frame

[Thomas Lumley]

On Wed, 15 May 2002, Beat Huggler wrote:

>
> Hi guys
 >
> I've got an easy question but couldn't find any quick solution. I woulk
> like to change the following matrix
>
> 		good 	bad worse
> Blue		1	2 	2
> Yellow	2	1	3
> Black		3	4	4
>
> Into the following structure
>
> good	1	Blue
> Bad	2	Blue
> Worse	2	Blue
> Good	2	Yellow
> Bad	1	Yellow
> Worse	2	Yellow
> Good	2	Black
> Bad	4	Black
> Worse	4	Black
>

reshape() will do this, but you need a dataframe and need the `colors' to
be a column of the data frame, so if it is really a matrix

df<-as.data.frame(X)
df$colors<-colnames(X)

A simple version is

reshape(df,direction=long, varying=list(c("good","bad","worse")))
     color time good id
1.1   Blue    1    1  1
2.1 Yellow    1    2  2
3.1  Black    1    2  3
1.2   Blue    2    2  1
2.2 Yellow    2    1  2
3.2  Black    2    4  3
1.3   Blue    3    2  1
2.3 Yellow    3    3  2
3.3  Black    3    4  3

and more precisely what you want is

reshape(df,direction="long",varying=list(c("good","bad","worse")),times=c("good","bad","worse"),idvar="color")
              color  time good
Blue.good      Blue  good    1
Yellow.good  Yellow  good    2
Black.good    Black  good    2
Blue.bad       Blue   bad    2
Yellow.bad   Yellow   bad    1
Black.bad     Black   bad    4
Blue.worse     Blue worse    2
Yellow.worse Yellow worse    3
Black.worse   Black worse    4


As you can see, reshape() is overdesigned for a problem like
this, but I assume your problem is in fact more complicated.

	-thomas

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._