similar to: can't understand "R"

Hi All, Sorry if this is a repost (a quick browse didn't give me the answer). I wonder if there are packages that can do the feature selection and classification at the same time. For instance, I am using SVM to classify my samples, but it's easy to get overfitted if using all of the features. Thus, it is necessary to select "good" features to build an optimum hyperplane (?).

Dear All, I've read Thomas Lumley's fortune "If the answer is parse() you should usually rethink the question.". But I am not sure it that also applies (and why) to other situations (Lumley's comment http://tolstoy.newcastle.edu.au/R/help/05/02/12204.html was in reply to accessing a list). Suppose I have similarly called functions, except for a postfix. E.g. f.1 <-

Dear R People: I am having some trouble with the snow package. It requires MPICH2 and Rmpi. Rmpi is fine. However, I downloaded the MPICH2 package, and installed. There is no mpicc, mpirun, etc. Does anyone have any suggestions, please? Thanks in advance! Sincerely, Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto:

Dear All, I've got into the habit of installing R from the precompiled Debian binaries, including many of the packages from the r-cran-* Debian packages, and later building from source (e.g., to link against Goto's BLAS, or to build patched versions, etc). I install the newly built R to the very same place (/usr/lib/R). This allows me to build and update R when I wish, AND provides the

Hello! I'm calling R from Perl with Statistics-R perl module for a microarray analysis integrated web tool. I have some questions for a multi-users utilisation: - Can I change the directory where R is running in order to have a directory per user? Then no problem of erasing R data of an other user. - If it's not possible, can I limite the number of users at the same time? I see

Is there a colinearty function implemented in R? I have tried help.search("colinearity") and help.search("collinearity") and have searched for "colinearity" and "collinearity" on http://www.rpad.org/Rpad/Rpad-refcard.pdf but with no success. Many thanks in advance, Peter Lauren.

Hi, does anybody know how to use the dual processors in the machines of a cluster? I am using R with rpvm and snow packages. I usually start pvm daemon and add host machines first, and then run R to start my computing work. But I find that only one processor in each machine is used in this way and the other one always stays idle. Is there any simple way to tell pvm to use the two processors at

Hi everyone, I am trying to cross-compile a package I wrote using the Yan and Rossini tutorial "Building Microsoft Windows versions of R and R packages using Intel Linux". I have got reasonably far with this but when doing the linking using the line: i586-mingw32-g++ -shared -s -o mylibrary.dll mylibrary.def mylibrary.o mylibrary_res.o

Greetings! I have a few colleagues who like the idea of Sweave, but have failed to become enlightened monks of the One True Editor (http://www.dina.dk/~abraham/religion/) Are there any other Microsoft-centric editors or IDEs which have solid support for writing SWeave documents (dual R / LaTeX enhancements similar to ESS's support)? Has anyone tried the folding editors which support Noweb?

Hi all, In Tibshirani's PNAS paper about nearest shrunken centroid analysis of microarrays (PNAS vol 99:6567), they used cross validation to choose the amount of shrinkage used in the model, and then test the performance of the model with the cross-validated shrinkage in separate independent testing set. If I don't have the luxury of having independent testing set, can I just use the

Dear all, not really a R question but: If I want to check for the classification accuracy of a LDA with previous PCA for dimensionality reduction by means of the LOOCV method: Is it ok to do the PCA on the WHOLE dataset ONCE and then run the LDA with the CV option set to TRUE (runs LOOCV) -- OR-- do I need - to compute for each 'test-bag' (the n-1 observations) a PCA

Hi Everyone, I have a question about for loops. If you have something like: f <- function(x) { y <- rep(NA,10); for( i in 1:10 ) { if ( i > 3 ) { if ( is.na(y[i-3]) == FALSE ) { # some calculation F which depends on one or more of the previously generated values in the series y[i] = y[i-1]+x[i]; } else { y[i] <- x[i]; } } } y } e.g. >

Hi Everyone, I have a question about for loops. If you have something like: f <- function(x) { y <- rep(NA,10); for( i in 1:10 ) { if ( i > 3 ) { if ( is.na(y[i-3]) == FALSE ) { # some calculation F which depends on one or more of the previously generated values in the series y[i] = y[i-1]+x[i]; } else { y[i] <- x[i]; } } } y } e.g. >

Hello everyone, I've been fiddling around with the snow and Rmpi packages on my new Intel Mac, and have run into a few problems. When I make a cluster on my machine, both slaves start up just fine, and everything works as expected. When I try to make a cluster including another networked machine it hangs. I've followed the suggestions at

Has anybody tried to use Rmpi with the OpenMPI library instead of LAM/MPI? LAM appears to be somewhat hardcoded in the Rmpi setup. Before I start to experiment with changing this, has anybody else tried Rmpi with non-LAM MPI implementations? Dirk -- Hell, there are no rules here - we're trying to accomplish something. -- Thomas A. Edison

I would like to buy a basic statistics book (experimental design, sampling, ANOVA, regression, etc.) with examples in R. Or download it in PDF or html format. I went to the CRAN contributed documentation, but there were only R textbooks, that is, textbooks where R is the focus, not the statistics. And I would like to find the opposite. Other text I am trying to find is multivariate data

Dear List, the advent of multicore machines in the consumer segment makes me wonder whether it would, at least in principle, be possible to divide a computational task into more slave R processes running on the different cores of the same processor, more or less in the way package SNOW would do on a cluster. I am thinking of simple 'embarassingly parallel' problems, just like inverting

Hi Thomas, see these papers or books (some are available on the web): Diego Kuonen, Introduction au data mining avec R : vers la reconqu??te du `knowledge discovery in databases' par les statisticiens. Bulletin of the Swiss Statistical Society, 40:3-7, 2001. Consultabile all??indirizzo web: http://www.statoo.com/en/publications/2001.R.SSS.40/ Diego Kuonen and Reinhard Furrer, Data mining

Like kile for LaTeX, Linux/KDE's kate editor is an excellent editor for R, with easy code submission to a running R process. Syntax highlighting is good. I have not been able to figure out two things: - how to automatically reformat a line or region of text using good indentation rules (Emacs/ESS make this so easy by just hitting Tab while the cursor is in a line, or highlighting a

I have 3 years of experience with R and have an interest in becoming a better programmer so that I might someday be able to contribute packages. Other than R, my only experience was taking Lisp from Daniel Friedman in the 1970's. I would like to learn either C or C++ for several reasons: To gain a better concept of object oriented programming so that I can begin to use S4 methods in R. To