Displaying 2 results from an estimated 2 matches for "universesize".
2004 Sep 24
1
algorithm reference for sample()
...Don't know if it belongs to r-devel or r-help, but since I am planning
to alter some of R's internal code I am sending it here.
The existing implementation of the sample() function, when the optional
'prob' argument is given, is quite inefficient. The complexity is
O(sampleSize * universeSize), see ProbSampleReplace() and
ProbSampleNoReplace() in random.c. This makes the function impractical
for the vector sizes I use. I want to re-code these functions and I
"think" I can come up with a more efficient algorithm. However before I
go and reinvent the wheel I wonder if there is...
2004 Sep 24
1
algorithm reference for sample() - Knuth
...ce I
> am planning
> >to alter some of R's internal code I am sending it here.
> >
> >The existing implementation of the sample() function, when
> the optional
> >'prob' argument is given, is quite inefficient. The complexity is
> >O(sampleSize * universeSize), see ProbSampleReplace() and
> >ProbSampleNoReplace() in random.c. This makes the function
> impractical
> >for the vector sizes I use. I want to re-code these functions and I
> >"think" I can come up with a more efficient algorithm.
> However before I
>...