On Oct 11, 2010, at 10:16 AM, clee wrote:
I have data that looks like this:
start end value
1 4 2
5 8 1
9 10 0
I want to transform the data so that it becomes:
startend value
1 2
2 2
3 2
4 2
5 1
6 1
7 1
8 1
9 0
10 0
> do.call("rbind",
apply(dta, 1,
function(.r) matrix(c(
seq(.r[1], .r[2]),
vals=rep(.r[3], .r[2]-.r[1]+1) ),
ncol=2) ))
[,1] [,2]
[1,] 1 2
[2,] 2 2
[3,] 3 2
[4,] 4 2
[5,] 5 1
[6,] 6 1
[7,] 7 1
[8,] 8 1
[9,] 9 0
[10,] 10 0
----
I've written a for loop that can do the transformation BUT I need to
do this
on very large datasets (millions of rows). Does anyone know of an R
package
that has a function that can do this transformation?
Any help is much appreciated!
Thanks!
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