similar to: Laptop freezes when trying to load R packages?

Let A be a m by n matrix and b a length n vector. What is the fastest vectorized code for doing for(j in 1:n) A[, j] <- A[, j]/b[j] ? solution 1: t(t(A)/b) solution 2: B <- matrix( rep(b, m), byrow=T, nrow=m ) A/B anything else? I have a program that uses this kind of operation million of times and I appreciate your input. Thanks. Jason Liao ===== Jason G. Liao Department of

Greetings. These days I find myself writing a lot of functions to handle routine things. One of these is a function to create a scatterplot of variables and draw a lowessed line so I can get some idea if there's any relationship between them. lowessed.plot <- function(x, y) { plot(x, y) lines(lowess(x, y)) } However, there's a slight problem: the plot axes come out labeled

This is some kind of follow-up to my previous posts. I have further improved the speed of my program 6 times by eliminating all the apply(). It turns out that apply is slow, is slower than direct loop, it is an order slower than a matrix operation alternative. Here is one example. The first apply version runs 19 seconds, the second loop version runs 13 seconds, the third matrix version runs 1

Dear listers, I need to export a distance matrix in the following format : a 0.0 1.0 0.2 1.0 1.0 b 1.0 0.0 1.0 1.0 1.0 c 0.2 1.0 0.0 1.0 1.0 d 1.0 1.0 1.0 0.0 1.0 e 1.0 1.0 1.0 1.0 0.0 I tried write.matrix() from the MASS library, which gives: a b c d e 0.0 1.0 0.2 1.0 1.0 1.0 0.0 1.0 1.0 1.0 0.2 1.0 0.0 1.0 1.0 1.0 1.0 1.0 0.0 1.0 1.0 1.0 1.0 1.0 0.0 Does anyone know of an R trick to change

Greetings. Is there any way to get R to take a regression model object and draw a plot of the regression function? How about overlaying that plot over a scatterplot of the actual data? Thanks in advance for any help anyone can provide. Aaron ----- Aaron Solomon?? (??ben Saul Joseph??) ??Adelman E-mail??: ??adelmaas at musc.edu Web site??: ??http??://??people.musc.edu??/??~adelmaas??/??

Greetings. I'm trying to recreate in R some regression models I've done in SAS, but I'm not getting the same results. My advisor suspects this may be due to differences in precision between R and SAS. Does anyone know where I can find specifications for R's type double? (It doesn't seem to be in the R Language Definition.) Thanks in advance for any help anyone can

Greetings. Yesterday I managed to jury-rig a system to get a table out of R and import it into Nisus Writer Express (a word processor for Mac OS X). What I came up with is brittle, since it depends on an AppleScript script which has to be in a specific location and on no one touching the computer, since the AppleScript remotely controls Nisus Writer Express rather blindly and will make

Dear Listers, I am trying to match tables that DO NOT have the same length. The tables result from the function "table()" so they look like this: table 1 2 3 4 3 5 7 table 2 1 2 3 6 4 5 I need the following output: (NOTICE THE ZEROS) 1 2 3 4 table1 0 3 5 7 table2 6 4 5 0 Unfortunately, I was not successful using "match()". Previous postings explain how to do

Greetings. I'm getting started learning R, and I'm trying to reproduce some models I've done previously in SAS. I'm trying to fit simple Poisson regressions, and I keep getting impossible results: the models predict negative numbers of cases for many observations. The code for the models are: Female.model <- glm(Observed ~ Black + Other, family = poisson(link=log),

Sorry for the extra info required, but I had digest mode turned on and wouldn't have received the mailing till tomorrow. I have since updated the data manually, but after 'yum update tzdata' was run, the zdump -v for EST5EDT and America/New_York all still showed a date of April 1, instead of March 11. After manually fixing, it is correct. This was mostly a question about why yum

I've been trying to learn about dynamically loading subroutines in R. Ultimately I would like to use this approach to implement some simulations. For the moment though, I've run into a problem compiling c++ code and loading it into R. The 'C/C++' and 'R'code below works fine when compiled and linked with gcc, but gives an error when the library is compiled and linked with

Dear listers, I am trying to assess variance components for a nested, mixed-effects model. I think I got an answer that make sense from R, but I have a warning message and I wanted to check that what I am looking at is actually what I need: my data are organized as transects within stations, stations within habitats, habitats within lagoons. lagoons: random, habitats: fixed the question is:

Hello, everyone! I picked up R several months ago and have adopted it as my choice for statistical programming. Coming from a Java background, I can honestly say that R is not only free, it is better tha S-plus: the lexical scope in R makes it very simple to simulate Java's object model. For this, I encourage everyone to read the artcle: Robert Gentleman and Ross Ihaka (2000) "Lexical

Dear Listers, I emailed the list a few days ago about how to bootstrap a community matrix (species by sites) and get a consensus tree with node support. A friend pointed out that a similar question remained unanswered in 2004. I wish to re-word my question: is anyone aware of a package / method to obtain a majority-rule consensus tree from x distance matrices ? Is anyone using R to generate

Hello all, R just ''stopped working'' on my machine (ibook g4, os 10.3.9). between last time I used it and now, I did not do anything but check emails and browse the internet. when I try to start the GUI, it appears and disappears as rapidly. when I tried to run a session from the terminal, I got the following: mkdir: /tmp/Rtmp590-29493: Permission denied mkdir:

I tested moving a box from Tao 1.0 to CentOS 3.7. All went well, as far as I can tell, with the OS upgrades, but I needed to rpm -ivh --force the desktop-* stuff. This was a minor thing to fix for no real purpose other than to just be doing it. I still get, though, the Tao screens when the graphic login screen appears. I have changed the Application->Settings->Login Screen->

I apologize for this very naïve and stupid question. I have searched the archives and "googled" a number of different queries relating to this question and cannot find the answer. My Division is moving toward running an application server for all statistical applications because the Department of Veterans' Affairs has their computers locked down. They are locked down so much so

Question, I have made numerous attempts at configuring the samba 2.3.3a program to include support for MIT Kerberos 5 v.1.2.3. The configure -help says that the switch to turn it on is"--with-krb5=base-dir". I have tried several different directories as the base-dir with no luck. During the coufigure, completes but the with-krb5 options is set to "no". The only time I

Hi, I have worked long and hard and looked in the manuals and am having a hard time constructing a diagonal matrix. I can get the diagonals out of a matrix but can't construct the matrix with just the diagonals. I have been on the web site and manuals and I think that it says to use: dsj <- diag (three = 1, nrow, ncol = 7) three is the name of my matrix and

I'm running CentOS 3 and have just installed a Liteon lightscribe DVD/CD unit. I firstly realized I didn't know exactly how to mount it, as /dev/dvd didn't exist, I didn't want to generate anything if it already existed, and I didn't want to mess up my cdrom unit that works just fine. I mounted the device though the X window just to see how it might mount, and find that it