[R] extraction from a list of vectors
jmiller at xcaliber.com
Mon Jun 18 00:10:26 CEST 2001
I know this should be easy, but I haven't figured out a fast way to
I have a list of vectors: mylist <- list(vector1, vector2, ...,
(The vectors are made of integers. They vary in length from about 1
I also have a vector of indices: myidx <- c( i1, i2, ..., iN).
From these I'd like to make this: newvector <- c(vector1[i1],
vector2[i2], ..., vectorN[iN]).
It's easy to do this using a for loop, but I need something that
will be fast for lists
with lengths of about 100,000. I've thought about using lapply, but
don't see how I can use it with "myidx".
Thanks in advance,
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