Hi,
I am very new to R, so I apologize if I have missed some trivial thing in
the manuals/archives. I am trying to get rid of for loops in my code and
replace them with R vector magic (with no success).
Let's say I have 2 vectors of the same length:
a <- c(2, 3, 7, 5)
b <- c(4, 7, 8, 9)
What I'd like to do is to generate a list(?) of 4 sequences using a[i] as a
start indices, and b[i] as end indices:
2,3,4
3,4,5,6,7
7,8
5,6,7,8,9
My first guess: "a:b", of course, does not work - only one sequence gets
generated using the first values from both vectors, plus a warning. Is there
a special syntax I can use to make ":" treat its operands as vectors?
More generally, is there a standard way to apply some arbitrary functions to
two or more vectors in an element-by-element fashion? For instance, sum(a,b)
will sum all values in both vectors; how can I make it produce a vector of
pairwise sums instead?
Thank you,
Anuta
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