similar to: When to set small values to 0?

Displaying 20 results from an estimated 10000 matches similar to: "When to set small values to 0?"

2008 Nov 23
2
How is R working in multicore and multiprocessor environment?
My Dear R buddies, I'm feeling ashamed that I've been running my R program on some servers for a while but do not know exactly how R is working. The servers are chained together using Sun Grid Engine. Each node has 8 quad-core CPUs. I wonder how many cores and CPUs are used by a simple single-thread R program. Thanks a lot. Best wishes, -- ??? Hesen Peng
2008 Nov 29
2
Reading mixed tables
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
2008 Sep 11
1
Convex optimization in R?
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
2009 Jul 11
1
Conditional expand.grid()
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
2008 Nov 24
2
More than doubling performance with snow
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 <-
2008 Aug 12
2
Multiple column/row names?
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/
2008 May 18
2
*apply function for arrays?
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
2009 Oct 27
1
How to express a tree?
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
2008 Oct 08
5
ParallelR
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
2009 Aug 06
5
Is there a 'vi' mode in R?
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
2009 Jun 16
1
Constrained Optimization, a full example
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
2008 Jan 18
1
Fortran level mismatch between package and R
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
2020 Jun 29
2
[PATCH] xen: introduce xen_vring_use_dma
> Subject: Re: [PATCH] xen: introduce xen_vring_use_dma > > On Mon, Jun 29, 2020 at 03:05:19AM +0000, Peng Fan wrote: > > > Subject: Re: [PATCH] xen: introduce xen_vring_use_dma > > > > > > On Thu, Jun 25, 2020 at 10:31:27AM -0700, Stefano Stabellini wrote: > > > > On Wed, 24 Jun 2020, Michael S. Tsirkin wrote: > > > > > On Wed, Jun
2020 Jun 29
2
[PATCH] xen: introduce xen_vring_use_dma
> Subject: Re: [PATCH] xen: introduce xen_vring_use_dma > > On Mon, Jun 29, 2020 at 03:05:19AM +0000, Peng Fan wrote: > > > Subject: Re: [PATCH] xen: introduce xen_vring_use_dma > > > > > > On Thu, Jun 25, 2020 at 10:31:27AM -0700, Stefano Stabellini wrote: > > > > On Wed, 24 Jun 2020, Michael S. Tsirkin wrote: > > > > > On Wed, Jun
2016 Mar 15
2
instrumenting device code with gpucc
Hi Jingyue, Sorry to ask again, but how exactly could I glue the fatbin with the instrumented host code? Or does it mean we actually cannot instrument both the host & device code at the same time? Thanks! yuanfeng On Tue, Mar 15, 2016 at 10:09 AM, Jingyue Wu <jingyue at google.com> wrote: > Including fatbin into host code should be done in frontend. > > On Mon, Mar 14, 2016
2003 Mar 04
2
How to extract R{i} from lme object?
Hi, lme() users, Can some one tell me how to do this. I model Orthodont with the same G for random variables, but different R{i}'s for boys and girls, so that I can get sigma1_square_hat for boys and sigma2_square_hat for girls. The model is Y{i}=X{i}beta + Z{i}b + e{i} b ~ iid N(0,G) and e{i} ~ iid N(0,R{i}) i=1,2 orth.lme <- lme(distance ~ Sex * age, data=Orthodont, random=~age|Subject,
2020 Jun 29
4
[PATCH] xen: introduce xen_vring_use_dma
> Subject: Re: [PATCH] xen: introduce xen_vring_use_dma > > On Thu, Jun 25, 2020 at 10:31:27AM -0700, Stefano Stabellini wrote: > > On Wed, 24 Jun 2020, Michael S. Tsirkin wrote: > > > On Wed, Jun 24, 2020 at 02:53:54PM -0700, Stefano Stabellini wrote: > > > > On Wed, 24 Jun 2020, Michael S. Tsirkin wrote: > > > > > On Wed, Jun 24, 2020 at
2020 Jun 29
4
[PATCH] xen: introduce xen_vring_use_dma
> Subject: Re: [PATCH] xen: introduce xen_vring_use_dma > > On Thu, Jun 25, 2020 at 10:31:27AM -0700, Stefano Stabellini wrote: > > On Wed, 24 Jun 2020, Michael S. Tsirkin wrote: > > > On Wed, Jun 24, 2020 at 02:53:54PM -0700, Stefano Stabellini wrote: > > > > On Wed, 24 Jun 2020, Michael S. Tsirkin wrote: > > > > > On Wed, Jun 24, 2020 at
2009 Dec 02
1
Fw: Re: Help: barchart() {Lattice}
I HAVE BEEN ASKED TO BE REMOVED FROM THIS LIST OVER 20 TIMES, PLEASE CAN I BE REMOVED!!!!!!!!!!!!! --- On Thu, 3/12/09, Peng Cai <pengcaimaillist@gmail.com> wrote: From: Peng Cai <pengcaimaillist@gmail.com> Subject: Re: [R] Help: barchart() {Lattice} To: "Felix Andrews" <felix@nfrac.org> Cc: r-help@r-project.org Received: Thursday, 3 December, 2009, 10:17 AM Got it
2016 Mar 13
2
instrumenting device code with gpucc
Hey Jingyue, Thanks for being so responsive! I finally figured out a way to resolve the issue: all I have to do is to use `-only-needed` when merging the device bitcodes with llvm-link. However, since we actually need to instrument the host code as well, I encountered another issue when I tried to glue the instrumented host code and fatbin together. When I only instrumented the device code, I