similar to: R-alpha: Sorting Efficiency

Hey guys, I tried to program quicksort like this but somethings wrong. please help >partition <- function(x, links, rechts){ > > i <- links > j <- rechts > t <- 0 > pivot <- sample(x[i:j],1) > > while(i <= j){ > > while(x[i] <= pivot){ > i = i+1} > > while(x[j] >= pivot){ > j = j-1} > > if( i

If one makes the reasonable assumption that Pct is much larger than Cutoff, sorting Cutoff is the expensive part e.g O(nlog2(n) for Quicksort (n = length Cutoff). I believe looping is O(n^2). Jeff's approach using findInterval may be faster. Of course implementation details matter. -- Bert On Mon, Oct 16, 2023 at 4:41?AM Leonard Mada <leo.mada at syonic.eu> wrote: > > Dear

> Only if the recursion is very deep. In practice, a recursive descent > parser isn't going to run out of stack space, nor will a quicksort or > binary-tree walker, The recursive-descent parser case has happened in practice: http://my.opera.com/hallvors/blog/2012/07/17/twitter-crashes-itself-with-commas?1 Also, I've seen some recursion-related PR's in Clang, although I think

sort() and order() are not quite the same, as "one knows": o order allows breaking ties by more than one argument; o sort allows a 'partial' and 'na.last' argument Still, the following timing (on a `simple' UltraSparc I) suggest that actually two different algorithms are used > N <- 10000 > typeof(x0 <- 1:N) # --- x0 : already sorted --- [1]

On Wed, Oct 3, 2012 at 10:15 AM, Matthieu Moy <Matthieu.Moy at grenoble-inp.fr> wrote: > Preston Briggs <preston.briggs at gmail.com> writes: >> Think about costs asymptotically; that's what matters. Calls and >> returns require constant time, just like addition and multiplication. > > Constant time, but not necessarily constant memory. > > Deep recursion

howdy gurus, I'm new and green and I was hoping for a tiny bit of your expertise. I'm running out of virtual memory (heap?) when summing using tapply. I've already used --vsize=90M on my hpux machine. (details below) Can I pre-sort or something to prevent my error? thanks, John Strumila john.strumila at corpmail.telstra.com.au > gc()["Vcells","total"] [1]

Motivated by Deepayan's recent inquiries about the efficiency of the R 'quantile' function: http://tolstoy.newcastle.edu.au/R/devel/05/11/3305.html http://tolstoy.newcastle.edu.au/R/devel/06/03/4358.html I decided to try to revive an old project to implement a version of the Floyd and Rivest (1975) algorithm for finding quantiles with O(n) comparisons. I used

please reply to hdgbyi@public.guangzhou.gd.cn or bgpgong@hotmail.com, thank you. UNCERTAINTY PRINCIPLE IS UNTENABLE By reanalysing the experiment of Heisenberg Gamma-Ray Microscope and one of ideal experiment from which uncertainty principle is derived , it is found that actually uncertainty principle can not be obtained from these two ideal experiments . And it is found that

please reply to hdgbyi@public.guangzhou.gd.cn or bcpgong@hotmail.com, thank you. UNCERTAINTY PRINCIPLE IS UNTENABLE By reanalysing the experiment of Heisenberg Gamma-Ray Microscope and one of ideal experiment from which uncertainty principle is derived , it is found that actually uncertainty principle can not be obtained from these two ideal experiments . And it is found that

Hi all, I want to compile the source code of Advanced Programming in the Unix Environment(APUE) 3rd edition, and I encountered some difficulties. After executing "make", I got this message: gcc -ansi -I../include -Wall -DLINUX -D_GNU_SOURCE barrier.c -o barrier -L../lib -lapue -pthread -lrt -lbsd /tmp/cc0gG99O.o: In function `thr_fn': barrier.c:(.text+0x6e): undefined reference to

Hello. I'm using these commands to compile the code below in order to collect edge/blocks profiling: clang -emit-llvm -c sort.c -o sort.bc opt -insert-edge-profiling sort.bc -o sort_prof.bc clang sort_prof.bc -lprofile_rt -L/llvms/lib -o sort_prof then I run the program and display the profiling information using llvm-prof sort_prof.bc, and the result is:

Hi, I implemented a garbage collector for a language I wrote in college using the llvm gc statepoint infrastructure. Information for statepoints: https://llvm.org/docs/Statepoints.html Example usage of parsing the llvm stackmap can be found at: https://github.com/dotnet/llilc/blob/master/lib/GcInfo/GcInfo.cpp https://llvm.org/docs/StackMaps.html#stackmap-format

Jakob Stoklund Olesen <stoklund at 2pi.dk> writes: > +10.0% SingleSource/Benchmarks/CoyoteBench/huffbench > +12.0% SingleSource/Benchmarks/McGill/chomp > +18.0% SingleSource/Benchmarks/BenchmarkGame/n-body > +45.5% SingleSource/Benchmarks/BenchmarkGame/puzzle > +10.0% SingleSource/Benchmarks/Shootout/heapsort > +10.5%

Everyone, There is non-determinism in LLVM codegen in the following scenarios: 1. Between back-to-back runs of the same LLVM toolchain 2. Between Release vs Release+Asserts toolchains 3. Between Linux vs Windows toolchains The main reasons for the non-determinism in codegen are: 1. Iteration of unordered containers (like SmallPtrSet, DenseMap, etc) where the iteration order is undefined 2.

The OS X configure in R-devel has been changed to use two-level namespaces. There are still some problems. 1. Trunmed.c in the modreg packages defines a function heapsort(), while heapsort is also defined (differently) in /usr/lib/stdlib.h. I (temporarily) disabled the definition in stdlib.h. 2. If R is configured with the --without-x flag, then CPPFLAGS does not include /usr/X11R6/include,

> On 2016-Nov-15, at 15:16, Hal Finkel <hfinkel at anl.gov> wrote: > > ----- Original Message ----- >> From: "Mandeep Singh via llvm-dev Grang" <llvm-dev at lists.llvm.org> >> To: llvm-dev at lists.llvm.org, "mehdi amini" <mehdi.amini at apple.com>, dexonsmith at apple.com, zinob at codeaurora.org >> Sent: Tuesday, November 15, 2016

Hi all, I am just curious how to sort the groups in a categorical box plot chart bwplot here is the example: d<-data.frame(sample(rep(month.abb,20), 100), runif(100,1,10)); colnames(d) <- c("Month", "Value"); bwplot(d$Month ~ d$Value); as you can see Months are not sorted alphabetically. Does anybody know ho to sort those on the chart level? Thank you Jan

# How would you best perform a secondary sort on :buildings below? = ''Building Name'' = select_tag ''building_id'', | option_groups_from_collection_for_select(Site.all(:order => :full_name), | :buildings, :full_name, :id, :full_name, nil) | -- Thanks, Tyler Arrigoni President OneInterface.net Network Engineering, Inc. 7475 North Palm, Suite 105, Fresno,

I see that one of the to-do's is to add a SmartTee filter to avicap32.dll. I have a microscope camera that is based upon a webcam (that I cannot set the proper resolution under Linux- and haven't gotten help to do so). I have software and drivers that will work in VirtualBox, but there is a 5 second delay between moving a slide in the window and the move showing up in the software

On Aug 19, 2007, at 20:43, Chris Lattner wrote: > On Aug 14, 2007, at 4:35 AM, Gordon Henriksen wrote: > >> On Aug 14, 2007, at 06:24, Gordon Henriksen wrote: >> >>> The two major problems I had really boil down to identifying GC >>> points in machine code and statically identifying live roots at >>> those GC points, both problems common to many