Hi,
I'm accessing a vertex attribute in R using V(g)$x, where x is a named
numeric attribute. If I do this for the whole graph (about 10e5 vertices),
it takes a few ms to get a vector of x values,
vx <- V(g)$x
If I then use vx as a target vector in an R loop to search through about
10e3 candidate y values for x, it takes maybe 100 ms,
for(i in 1:length(y))
{
z <- which(vx > y[i])
}
However, if I substitute V(g)$x for vx INSIDE the loop, it takes about 5s
- more than 50x slower. Why is this?
Thanks
Tony
Dr. Tony R. Larson
CNAP
Department of Biology, Area 7
University of York
Wentworth Way
Heslington
York YO10 5DD
UK
Tel: +44(0)1904 328 826 (office)
Tel: +44(0)7833 471 685 (mobile)
[email protected]
http://scholar.google.com/citations?user=9hLFka4AAAAJ
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