[R] Reshaping matrix of vectors as dataframe

[Oliver Gondring]

Dear R people,

I have to deal with the output of a function which comes as a matrix of 
vectors.
You can reproduce the structure as given below:

x <- list(c(1,2,4),c(1,3,5),c(0,1,0),
           c(1,3,6,5),c(3,4,4,4),c(0,1,0,1),
           c(3,7),c(1,2),c(0,1))
data <- matrix(x,byrow=TRUE,nrow=3)
colnames(data) <- c("First", "Length", "Value")
rownames(data) <- c("Case1", "Case2", "Case3")

 > data
       First     Length    Value
Case1 Numeric,3 Numeric,3 Numeric,3
Case2 Numeric,4 Numeric,4 Numeric,4
Case3 Numeric,2 Numeric,2 Numeric,2

 > data["Case1",]
$First
[1] 1 2 4

$Length
[1] 1 3 5

$Value
[1] 0 1 0
--------------------

My goal now is to break the three vectors of each row of the matrix into 
their elements, assigning each element to a certain "Sequence" (which I 
want to be numbered according to the position of the corresponding 
values within the vectors), reshaping the whole as a data frame like this:

Case	Sequence	First	Length	Value

Case1	1		1	1	0
Case1	2		2	3	1
Case1	3		4	5	0

Case2	1		1	3	0
Case2	2		3	4	1
Case2	3		6	4	0
Case2	4		5	4	1

Case3	1		3	1	0			
Case3	2		7	2	1

I suspect that there might be an elegant and not too complicated way to 
do this with one or several of the functions provided by the 'reshape' 
package, but due to my lack of experience with R in general, this 
package in particular and the complexity of the task I wasn't able to 
figure out how to do it so far.

Every hint or helpful comment is much appreciated!

Oliver