similar to: OT: Any reason why one of my computers is so slow?

Dear all, Indexing matrices from the Matrix package with [i,j] seems to be very slow. For example: library(rbenchmark) library(Matrix) mm <- matrix(c(1,0,0,0,0,0,0,0), nr=20, nc=20) MM <- as(mm, "Matrix") lookup <- function(mat){ for (i in 1:nrow(mat)){ for (j in 1:ncol(mat)){ mat[i,j] } } } benchmark(lookup(mm), lookup(MM),

The low speed of writes with the MS-DOS, MS newtworking client has to do with the limit of MAXSENDSIZE (from TCPUTILS.INI) By default, the value is 1024, but the maximum value is 2048. If this value is not set to the same as the Samba server's SO_RCVBUF, then performence will suffer GREATLY. We had a Windows system hosting Norton Ghost images, but it took a dive, and our company has

Hi, everybody: I asked about this in r-help last week and promised a summary of answers. Special thanks to the folks that helped me understand do.call and pointed me toward plyr. We face this problem all the time. A procedure generates a list of data frames. How to stack them together? The short answer is that the plyr package's rbind.fill method is probably the fastest method that is not

Hi Berend, I see you are one of the contributors to the rbecnhmark package. I am sorry that I am bothering you again. I have tried to run your code (slightly tweaked) involving the benchmark function, and I am getting the following error message. What am I doing wrong? Error in benchmark(d1 <- s1(df), d2 <- s2(df), d3 <- s3(df), d4 <- s4(df), : could not find function

Hello, I'm migrating a mail server from a centos 5 cluster architecture to a centos 6 cluster architecture. The new cluster involves faster machines then the old cluster, and a virtual machine. I use dovecot-2.0.9-5.el6.x86_64, while the old cluster uses dovecot-2.0.1-1_118.el5. Tha mail server uses mysql for the users database, and a local ldap for authentication. The storage is also much

Dear list: I have a data frame with student name, class he attended and marks for subjects he attended. Students took second exam if they performed badly in their first attempt. I want to consider the test scores where they obtain highest median. there are 6 classes. As a sample case, I will consider only classes A, B and C. For class A, Student Raj took first exam and he did not score well.

Hmm. Chuck: I don't see how this example represents incomplete/incommensurate recycling. Doesn't TRUE replicate from length-1 to length-3 in this case (mat[c(TRUE,FALSE),2] would be an example of incomplete recycling)? William: clever, but maybe too clever unless you really need the speed? (The clever way is 8 times faster in the following case ...) x <- rep(1,1e6)

Dear Professor Revelle and R-helpers, This is a two-part question: the first part is general, and the second is specific to the psych package. First question: In the past I've constructed composite variables from questionnaire data by using rowMeans(), and then correlating items with the scale using cor() as an informal check for "bad" items. Over the weekend I decided to take a

If x is a (long) vector and n << length(x), what is a fast way of finding the top-n values of x? Some suggestions (calculating the ratio of the two top values): library("rbenchmark") set.seed(1); x <- runif(1e6, max=1e7); x[1] <- NA; benchmark( replications=20, columns=c("test","elapsed"), order="elapsed" , sort = {a<-sort(x,

Hi, I am passing a data frame and field name to a function. I've figured out how I can create the formula based on the passed in field name, but I'm struggling to create a vector based in that field. for example if I hard code with the actual field name Y = df$Target, everything works fine. but if I use the passed in parameter name, it doesn't give me what I want, Y = df$mytarget

I run Fedora 22 R package. It is build with --with-lapack \ --with-blas \ --enable-R-shlib \. As the machine will act as a server with lots of R data computing, I try to optimize my R package. At first, I installed parallel_studio_xe_2016 with a free one year licence. Then, I build a package for R with Intel MKL and compiler. This took me lots of time as it was my first .rmp build. I finally

Hi all, i am trying to compile a test, calling from C code R Lapack shared libraries. In particular, i am calling simple LAPACK driver dposv for solving linear equation system A*x=B with positive definite A. My code looks like the following in solve.c ========================== #include<stdio.h> #include <R_ext/BLAS.h> #include <R_ext/Lapack.h> int main(){

I have a character string and I would like to remove the leading and tailing white spaces. The example for 'sub' shows how to remove the trailing white spaces, but I still can't figure out how to remove both trailing and leading white spaces because I can't find any documentation for what "+$" means or what "\\s+$" means. Maybe its because I don't have a

I've had a lot of requests for additions to the reproducible research task view that fall into a grey area (to me at least). For example, roxygen2 is a tool that broadly enable reproducibility but I see it more as a tool for better programming. I'm about to check in a new version of the task view that includes packrat and checkpoint, as they seem closer to reproducible research, but also

Hi, I am passing a data frame and field name to a function. I've figured out how I can create the formula based on the passed in field name, but I'm struggling to create a vector based in that field. for example if I hard code with the actual field name Y = df$Target, everything works fine. but if I use the passed in parameter name, it doesn't give me what I want, Y =

WARNING - R newbie alert. =) I'm sorry, this may be a real stupid question - but why is plotting in R so slow? BTW, I've used R in Windows 2000 (1 Ghz Pentium 512MB RAM) and on Linux box (200 Mhz P2 64MB RAM) and had the same problem. I have CSV data sets that I load that sometimes have around 40000 data points in them. Here's what I do usually: >

What would cause the "View Workgroup Computers" to be slow in coming up. It will take from 10 seconds to 1 minute. A am using Windows XP hosts with an SCO OpenServer using Samba in a workgroup, and Samba is the preferred master (os 255) with WINS support. I have the Browser service turned off on all Windows clients. Thanks, Rick Cone Secure Payment Systems

I second the motion for a Programming Tools CRAN Task View. I would also think it could contain things like Rcpp, R6, etc. -Greg > On Jan 22, 2015, at 10:20 AM, Max Kuhn <mxkuhn at gmail.com> wrote: > > I've had a lot of requests for additions to the reproducible research > task view that fall into a grey area (to me at least). > > For example, roxygen2 is a tool

On Thu, 22 Jan 2015, Max Kuhn wrote: > I've had a lot of requests for additions to the reproducible research > task view that fall into a grey area (to me at least). > > For example, roxygen2 is a tool that broadly enable reproducibility > but I see it more as a tool for better programming. I'm about to check > in a new version of the task view that includes packrat and

All, Could anyone recommend a package that allows the user to constrain the coefficients from a multiple regression equation? I tried using the gl1ce function in lasso2, but couldn't get it to work. I created a contrived example to illustrate my starting point. data(cars) fmla <- formula(dist ~ speed) gl1c.E <- gl1ce(fmla, data = cars) gl1c.E gl1c.E <- gl1ce(fmla, data =