On 21/06/2010 9:06 PM, G FANG wrote:
Hi,
I want to get the unique set from a large numeric k by 1 vector, k is
in tens of millions
when I used the matlab function unique, it takes less than 10 secs
but when I tried to use the unique in R with similar CPU and memory,
it is not done in minutes
I am wondering, am I using the function in the right way?
dim(cntxtn)
[1] 13584763 1
uniqueCntxt = unique(cntxtn); # this is taking really long
What type is cntxtn? If I do that sort of thing on a numeric vector,
it's quite fast:
> x <- sample(100000, size=13584763, replace=T)
> system.time(unique(x))
user system elapsed
3.61 0.14 3.75
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