similar to: How is R working in multicore and multiprocessor environment?

Dear R buddies, This weekend I became interested in solving Google Code Jam problems using R. I guess R may work very well in this kind of contests but the input of file has been a problem for me. Take this case for example (http://code.google.com/codejam/contest/dashboard?c=agdjb2RlamFtchALEghjb250ZXN0cxjRzBQM), the files are usually of the form: A(number of lines for group 1) a11 a12 a13 a21

Hello my R buddies, I'm trying to generate a bivariate data.frame with the elements of first row greater than the second row. The more complicated method that I can think of is: n <- 10 temp <- expand.grid(1:n,1:n) temp<-temp[temp[,1]>temp[,2],] However, I guess there must be some easier way of doing this. Besides, if inequality condition is applied at the very

Hey my R buddies, I installed the "snow" and "rpvm" package on my Lenovo Thinkpad T400 today. The experiment below gave me a surprise. The time consumed by serial processing was several times larger than that taken by parallel processing. I'm very curious how this happened. Thank you very much. > library(snow) > > cc <- makePVMcluster(2) > > temp <-

Hi all, I wonder if there is a way to create a matrix with two (or even more) column/row names? Thank you very much. Have a nice day. -- ??? Hesen Peng http://hesen.peng.googlepages.com/

Hi my R buddies, I'm trying to solve a specific group of convex optimization in R. The admissible region is the inside and surface of a multi-dimensional eclipse area and the goal function is the sum of absolution values of the variables. Could any one please tell me whether there's a package in R to do this? Thank you very much, Best wishes, -- ??? Hesen Peng

My dear R buddies, I've run into a problem when doing numerical computation recently. In a program that I've been working on, I usually get a vector of real values which are theoretically (and it's correct) supposed to decrease until reaching zero after a given value. However, most of the value just wander at 10^-8 scale and never shrink exactly to zero. So I guess I should manually

Hi all, I've recently been writing functions which may deal with very large arrays. And I hope to use *apply functions in the program so that the code may look nicer and the performance may be better in the following two situations. The first situation is: I'm having an array A with dim(A)==c(m,n,p). And I want to apply a function F to a group of elements in A like: 1) F is applied to

Anyone using or has access to ParallelR? I was looking at the page and found nothing really useful! http://www.revolution-computing.com/sitegenius/topic.php?id=195 I want to see if I can run R on a cluster of workstation, and use batch systems like Grid Engine or Xgrid: http://gridengine.sunsource.net/ http://ww.apple.com/acg/xgrid/ --Chi

Hello everybody, I'm write a function whose output represents a tree. Can anyone please recommend me some data structure in R which are good for expressing a tree? The possible idea I'm having in my mind is to represent the whole tree as a list in which a sublist (an element to the main list) contains all its corresponding branches. Is there any simpler way of doing this? Thank you very

After a few days of work, I think I nearly have it. Unfortunately, theta is unchanged after I run this (as a script from a file). I thought that theta would contain the fitted parameters. The goal here is to find the least squares fit according to the function defined as "rss" subject to the constraints defined as ui and ci. I defined ui and ci to (hopefully) force par2 and par3

Hi, I'm wondering if R provide a vi mode in the command line just like other shells such as bash do. Can somebody let me know? Regards, Peng

We have a user here who is attempting to compile a package which requires f90 (gfortran will do). Our version of R was built with f77 (g77). When the user attempts to build the package, f77 is always invoked and fails due to the presence of f90 features. Is there a simple method or some documentation on how to force a package build to use a different compiler than the one used in

I have a program which needs to compute squared Euclidean distance between two vectors million of times, which the Rprof shows is the bottleneck. I wondered if there is any faster way than my own simple function distance2 = function(x1, x2) { temp = x1-x2 sum(temp*temp) } I have searched the R-help archives and can not find anything except when the arguments are matrices. Thanks for any

What's the best approach to running latent class analysis with R? I've downloaded both randomLCA and poLCA packages, but I am interesting in running a standard LCA with individual records (not frequency table) as input data. Wen Gu John Jay College of Criminal Justice445 West 59 StreetNew York, NY 10029 wgu@gc.cuny.edu _________________________________________________________________

I was wondering if anybody else had seen the following: I have a multiprocessor system (Intel P4). I use Wine to run the Tasking 56300 DSP compiler (Tasking, brilliant folks they are, *had* a Linux version, that they DROPPED support for!). Doing a build of a fairly large project (over a hundred files), with nothing much else going on, the compiles run very slowly, the system is at less than

Hi, I know it's not really the place, but if anybody in the UK (or US) is interested, I'm clearing out lots of new Cisco stock... 7970G's (colour LCD), 7960G's, 7940G's, 7920G's (wireless IP phone), 7935's (conference phone) and 3550-24-PWR switches. I also have boxes of 7914's, the single-7914 foot stand and double-7914 foot stand (these are required to

Hi all, I am experiencing issue on freshly upgraded Debian Squeeze with Xen 4.0.1 from Debian repositories. After upgrade the system with Xen was slow - no iowaits only Steal time was high. I tried workarounds regarding ACPI - only acpi=off was working but the performance decrease was quite large due to only one CPU core was active at that time. The last workaround I am running right now is to

Hi All, Was curious if anyone successfully running WinXP HVM (x86) under Xen 3.2.1 with the HAL set to "ACPI Multiprocessor" without using up oodles of CPU time?  Works great with "Standard PC" but would like to get all the CPU cores accessible for XP... -- Daniel Kao Übermind, Inc. Seattle, WA, U.S.A. _______________________________________________ Xen-users mailing list

Hi, What would I need to do to make wine run LotrO on just one core, or How do I set it to use both to test if that helps?

don't read this. i'm a complete newbie, and i don't know how to start sending messages. if someone read this, then can answer me also how to delete a file with the console (really ashamed) y know that copy with cp, but delete??? thanks... ___________________________________________________________ 1GB gratis, Antivirus y Antispam Correo Yahoo!, el mejor correo web del