similar to: Using sapply to build a count matrix

I am working on a methodology for qualifying R, for GLP and GCP. If I quailfy only the base R install, with no contributed packages, it seems relatively simple to qualify R. However, from time to time I will want to use a contributed package. If I use a contributed package, does it leave anything behind that will be loaded with the next invocation of R? Suppose I run R and use a contributed

There are a couple of points to keep in mind when doing a log-transform of an exponential model, such as -- y = a*exp(b*x) 1. The implicit statistical model is multiplicative in the error. The implied statistical model of the log transform is -- log(y) = log(a) + b*x + u which implies -- y = a*exp(b*x)*exp(u) A linear regression in the log

I have tried to install the "genetics" package and am getting and error. The log is below. For information, I am using R 2.10.1 on the Windows XP operating system. The mirror site I'm using is Michigan Technological University. Your help in this matter will be greatly appreciated. Murray M Cooper, PhD Richland Statistics 9800 North 24th St Richland, MI, USA 49083

Hi! I'm comparing the differences in contaminant concentration between 2 different groups of people ( N=36, N=37). When using a simple linear regression model I found no differences between groups, but when evaluating the diagnostic plots of the residuals I found my independent variable to have deviations from normality (even after log transformation). Therefore I have used bootstrap on

Hi all, I have a dataset which consists of 2 columns. I'd like to plot them on a x-y scatter plot and fit an exponential trendline. I'd like R to determine the equation for the trendline and display it on the graph. Since I am new to R (and statistics), any advice on how to achieve this will be greatly appreciated. Many thanks, Chris -- View this message in context:

Hi, I'm not used to thinking along these lines, and wanted to ask your advice: Suppose you have a sample of around 100, consisting of patients according to doctors, in which patients and doctors are given a questionnaire with categorical responses. Each patient somehow has roughly 3 doctors, or 3 rows of data. The goal is to assess by category of each question or DV the agreement between

Hi! I have some data that looks like this up down percentaje uew_21 20 14 58.82 uew_20_5 27 40 40.29 uew_20 8 13 38.09 uew_19_5 17 42 28.81 So I have 4 experimental conditions and I am counting number of animals in the up and down compartment and the calculating the percentage, I want to know which one of the conditions is different from each other. If the data wouldn't be percentage

Hi All, I downloaded the R program (version 2.6.2) in last Jan 2008. I now want to upgrade the program to its latest version, but I don't want to go through the process of deleting the existing version and downloading the new version. This is because my existing R program has numerous packages that I downloaded for my research work. I want to upgrade my R program with those packages in it. Is

I am working on a project that requires me to do very large factorial evaluations. On R the built in factorial function and the one I created both are not able to do factorials over 170. The first gives an error and mine return Inf. Is there a way to have R do these larger calculations (the calculator in accessories can do 10000 factorial and Maple can do even larger) -- View this message in

I have a few hundred files of formatted data. Unfortunately most of them end with a spurious CONTROL-Z. I want to rewrite the files without the spurious character. Here's what I've come up with so far, but my code is unsafe because it assumes without justification that the last row of df contains a control character (and some NAs to fill up the record). options(warn=-1) #turn off

I'm sure there is a more general way to ask this question but how do you use the elements of a character vector as names of objects in an expression? For example, say you have: a = c(1,3,5,7) b = c(2,4,6,8) n=c("a","b") and you want to use the names a and b in a function (e.g. sum) sum(eval(as.name(n[1])),eval(as.name(n[2]))) works but what is a simpler way to

Dear R-developers community, I have the following generic: setGeneric( name="newsample", def=function(x,y,z,a,b,c,...){standardGeneric("newsample")} And I can build several methods for this generic. One useful thing is to use "newsample" with only one of the 6 arguments listed. At the moment this is what I do: setMethod(

For a long time I've wanted a way to conveniently extract multiple elements from a list, which [[ doesn't allow. Can anyone suggest an efficient function to do this? Wouldn't it be a sensible addition to R? For example, alist <- list() alist[[1]] <- list() alist[[1]]$name <- "first" alist[[1]]$vec <- 1:4 alist[[2]] <- list() alist[[2]]$name <-

Hi folks: How do I get shell() or system() to run external programs in a particular directory (different from the current R working directory)? > version _ platform i386-pc-mingw32 arch x86 os Win32 system x86, Win32 status major 1 minor 3.0 year 2001 month 06

Greetings ~ I need some assistance determining an appropriate approach to analyzing multivariate binary response data, and how to do it in R. The setting: Data from an assay, wherein 6-hours-post-fertilization zebrafish embryos (n=20, say) are exposed in a vial to a chemical (replicated 3 times, say), and 5 days later observed for the presence/absence (1/0) of defects in several organ systems

Hi folks: I think I'm having problems with figuring this one out: test1 <- function() { n <- 2 for(i in 1:n) { cat(paste("i =", i, "\n")); flush.console() n <- 5 # version 1 #n <<- 5 # version 2 #assign("n", 5, envir = environment(test1)) # version 3 } } I need the for(.) loop to run (say) n=5 times within the

I've tried and give up. I have a matrix of say 200 columns and 400 rows. For each odd ( or even i suppose if i wanted to )column, I want to know the number of rows in which the value is greater than zero. So, I did sapply(tempMatrix,2,function(x) sum( x > 0 )) this almost works but i don't know how to tell it to only do the odd columns. my guess is , like everything else in R, this

The handy function summary() doesn't work correctly with Date class objects: > R.version.string [1] "R version 1.9.1, 2004-06-21" > b <- as.Date(c("2002-12-26", "2002-12-27", "2002-12-28", "2002-12-29", "2002-12-30")) > b [1] "2002-12-26" "2002-12-27" "2002-12-28" "2002-12-29"

Hi folks: This may be a stupid question, but I cannot seem to find a way to tell readBin that I want to read 2-byte integers from the connection. The input file is 150,720 bytes long containing 75,360 short (2-byte) integers. But specifying "integer" or "int" for what in readBin only returns me a vector of length 37680, leading me to believe that sizeof(integer) or

I have the same question that Eusebio had: Is there a function similar to "sink" that redirect also R code to a file that is: sink("R001") x <- c(2,-6,-4,8,5,4,1,3,4,-9,0,1) A <- matrix(x, ncol=3) A A.prima <- t(A) A.prima dim(A) dim(A.prima) sink() create a file "R001" with contents: ------------------------------------------ [,1] [,2] [,3] [1,]