similar to: Multiple column/row names?

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

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

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

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

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

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'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

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

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

Hi, I have a data frame with 100 variables (numeric and non numeric types), and I want to join them in only one column, like a vector, but i want to keep the non numeric variables like they are. I know that i can do something like this: Suppose that my data is in df variable new_df<-data.frame(c(df[,1],df[,2],df[,3],df[,4],...........) This works but i have 100 variables! Any way of doing

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

I am compiling 2.2.8 on a Caldera Openlinux box that was running 2.0.5 or some such. It already has a working config and uses samba.d dirs for it's files: /etc/samba.d /var/lock/samba.d /var/log/samba.d etc During compile I use following switches --with-piddir=/var/lock/samba.d --with-lockdir=/var/lock/samba.d However the pid files are ending up in /var/run/samba instead of