search for: probsamplenoreplace

Displaying 3 results from an estimated 3 matches for "probsamplenoreplace".

2004 Sep 24
1
algorithm reference for sample()
...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 a published description of an efficient sampling a...
2004 Sep 24
1
algorithm reference for sample() - Knuth
...#39;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 a publis...
2010 Mar 05
0
references to (1) R source code in svn repo within .Rd file and (2) to C source code in comments in R code using .Internal() /.Primitive()
...icer" ### ### corresponding C code may be inspected in ### https://svn.r-project.org/R/branches/% <linebreak> ### R-2-xx-branch/src/main/random.c ### ### <and, optionally something like> ### ### as functions ProbSampleReplace(), ProbSampleNoReplace(), ### SampleReplace(), SampleNoReplace(), ..... ### <maybe more> # ###end.new comment # } } --- snip --- (The actual list of C functions would not be urgent at all; finding the "right" source file alread...