Hi, I'm sure this is a fairly simple problem, but I can't seem to find any
specific information in the documentation as to what is going on. I am
writing a simple nearest neighbor program that takes in a set of of points
on a plane and returns the neighbors of those points, for a fixed number of
neighbors. However, the returned integer array that is allocated in R
seems to occasionally return incorrect results.
I thought this would be because of GC, but I thought this was only for
SEXPs, or at least this is the impression I got from reading the
documentation. So is there some obvious reason why my results seem to get
mangled by this call? I have checked my program through several thousand
loops in C, and always get the same results, so I assume that this is
something I'm doing wrong in R.
Here is the code for my .C call. I could post the C code if someone thinks
it's important, but I'm just changing the values of integer array specified
in R.
r.result <-
.C("evalPoly",
as.double(c.polygonX),
as.double(c.polygonY),
as.double(c.neighborX),
as.double(c.neighborY),
integer(c.numberOfNeighbors*c.height*c.length),
as.integer(c.polygonLength),
as.integer(c.neighborLength),
as.integer(c.numberOfNeighbors),
as.integer(c.length),
as.integer(c.height),
DUP=TRUE
)[[5]]
Cheers,
Jonathan
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