On Jan 31, 2010, at 9:53 AM, Oliver Gondring wrote:
Dear R people,
I have to deal with the output of a function which comes as a matrix
of vectors.
If that is so, then the object below does not represent it, because
that is a matrix of _lists_.
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
$Value
[1] 0 1 0
--------------------
My goal now is to break the three vectors of each row of the matrix
into their elements, assigning each element to a certain
"Sequence" (which I want to be numbered according to the position of
the corresponding values within the vectors), reshaping the whole as
a data frame like this:
This is close to what you specify:
> apply(data, 1, function(.x) cbind(1:length(.x$First), sapply(.x,
function(.y) return(.y ) ) ) )
$Case1
First Length Value
[1,] 1 1 1 0
[2,] 2 2 3 1
[3,] 3 4 5 0
$Case2
First Length Value
[1,] 1 1 3 0
[2,] 2 3 4 1
[3,] 3 6 4 0
[4,] 4 5 4 1
$Case3
First Length Value
[1,] 1 3 1 0
[2,] 2 7 2 1
And if you do.call(rbind, on the result you would get a matrix but
loose the case labeling.
Adding the Case labels proved to be a bit of a challenge to me. Maybe
one of the wizards will take pity on us:
> sapply(rownames(data), function(.x) cbind(.x,
# those were the rownames
cbind(1:length(data[.x, "First"][[1]]),
# and that was the incremental counter
sapply(data[.x, ],
#and finally the values which unfortunately get turned into characters
function(.y) return(.y ) ) ) ) )
$Case1
.x First Length Value
[1,] "Case1" "1" "1" "1" "0"
[2,] "Case1" "2" "2" "3" "1"
[3,] "Case1" "3" "4" "5" "0"
$Case2
.x First Length Value
[1,] "Case2" "1" "1" "3" "0"
[2,] "Case2" "2" "3" "4" "1"
[3,] "Case2" "3" "6" "4" "0"
[4,] "Case2" "4" "5" "4" "1"
$Case3
.x First Length Value
[1,] "Case3" "1" "3" "1" "0"
[2,] "Case3" "2" "7" "2" "1"
(I tried a couple of plyr efforts but that is not a package that I
have had much success with.)
--
David.
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
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
