similar to: Evaluating the Yield of Medical Tests

Hello, I am new to non-linear growth modelling in R and I am trying to reproduce an analysis that was done (successfully) in S-Plus. I have a simple non-linear growth model, with no nesting. I have attempted to simplify the call as much as possible (by creating another grouped object, instead of using subset= and compacting the fixed and random expressions.) This is a what the grouped

Please, I have a 2GB computer and a huge time-series to embedd, and i tried increasing memory.limit() and memory.size(max=TRUE), but nothing. Just before the command: > memory.size(max=TRUE) [1] 13.4375 > memory.limit() [1] 1535.875 > gc() used (Mb) gc trigger (Mb) max used (Mb) Ncells 209552 5.6 407500 10.9 350000 9.4 Vcells 125966 1.0 786432 6.0 496686 3.8

Dear colleagues, I'm conducting a meta-analysis of studies evaluating adherence of HIV-positive drug users into AIDS treatment, therefore I'm looking for some advice and syntax suggestion for running the meta-regression using proportions, not the usual OR/RR frequently used on RCT studies. Have already searched already several handbooks, R-manuals, mailing lists, professors, but... not

Hi all-- I am in the process of helping colleagues write up a ms in which we fit zero-inflated Poisson models. I would prefer plotting the rate ratios and 95% CI (as I've found Gelman and others convincing about plotting tables...), but our journals usually like the numbers themselves. Thus, I'm looking at a recent JAMA article in which both numbers and dotplot of RR and 95% CI are

Hi there, I'm writing a function which involves a loop. What to write in the "?" place would allow it skips the "for loop" and goes to "a[i]<-0". a<-b[s>3,] if (nrow(a)==0) ????????????? for (i in 1:nrow(a)){ a[i]<-1 } a[i]<-0 Lisa Wang Cancer Informatics, Ontario Cancer Institute/Princess Margaret Hospital,

I would like to track in which journals articles about a particular disease are being published. Creating a pubmed search is trivial. The search provides data but obviously not as an R dataframe. I can get the search to export the data as an xml feed and the xml package seems to be able to read it. xmlTreeParse("

Dear All, I would like to find something ( references, code,..) to implement a comparison of three treatments in an observational study using the 'Propensity Score'. Any help is much appreciated. Thanks! Giovanni -- dr. Giovanni Parrinello Department of Biotecnologies Medical Statistics Unit University of Brescia Viale Europa, 11 25123 Brescia email: parrinel at med.unibs.it Phone:

Dear all, I am comparing logistic regression models to evaluate if one predictor explains additional variance that is not yet explained by another predictor. As far as I understand Baron and Li describe how to do this, but my question is now: how do I report this in an article? Can anyone recommend a particular article that shows a concrete example of how the results from te following simple

This question is not oriented towards R, but is posted here because I have the impression that there are at least some Latex users among the contributors. The question is: What editors for Latex are to be recommended? I have located one: http://www.latexeditor.org/ What other alternatives are there? I am (for the most part) using Windows XP. Tom

Hello All, I'm struggling to solve this ODE using R, vdpol <- function (h, v, t) ( list(c ( -0.1*v/(pi*(2*10*h-h^2)), (v = (-0.1*v/(pi*(2*10*h-h^2))^2) + 2*9.81*h)) )) library(deSolve) yini <- (c(h = 20, v=0)) nonstiff <- ode(y = yini, func = vdpol, times= seq(0, 30, by =

Hi all, I'm using the medical risk package to determine the risk stratification Index based on the ICD9 codes. Although, I have been successful in using it, I'm unable to interpret the output. here is the sample code # Calculate RSI for each patient ("id") in dataframe cases <- data.frame(id=c(1,1,1,2,2,2,2,2), +

*Vacancy: Scientific Collaborator in Statistical Bioinformatics* *Institute for Medical Informatics, Statistics and Documentation**, Medical University of Graz, Austria* predoc level with PhD opportunity, 30 hours per week available from May 1st, 2012 *Tasks:* * Working in the project "Biostatistical-genomical analysis of the clinical relevance of liver cancer models" which is

Dear All, I have just read a glowing review (in the Int. Journal of Epidemiology) of "Analyzing Medical Data Using S-PLUS" by Everitt and Rabe-Hesketh and it sounds like the sort of thing I would like to get my hands on. Is anyone on this list familiar with this book, and in particular have a feel for how useful it will be with R? According to the review the emphasis is on the command

Dear all, The "tractor.base" package has recently been added to CRAN. This package provides functions to read, write, visualise and manipulate magnetic resonance images. The standard Analyze, NIfTI and DICOM file formats are supported (read-only for DICOM), and all metadata is stored with the image data internally. The code can be used to visualise image slices or maximum intensity

Dear all, The "tractor.base" package has recently been added to CRAN. This package provides functions to read, write, visualise and manipulate magnetic resonance images. The standard Analyze, NIfTI and DICOM file formats are supported (read-only for DICOM), and all metadata is stored with the image data internally. The code can be used to visualise image slices or maximum intensity

dcemri 0.10 has been released on CRAN "dcemri" is (to the best of my knowledge) the first public-domain software package for the quantitative analysis of dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI or DWI). Data import and export is availble for ANALYZE or NIfTI data formats (sorry, no DICOM). Images are stored in neurological format regardless of the

dcemri 0.10 has been released on CRAN "dcemri" is (to the best of my knowledge) the first public-domain software package for the quantitative analysis of dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI or DWI). Data import and export is availble for ANALYZE or NIfTI data formats (sorry, no DICOM). Images are stored in neurological format regardless of the

dcemriS4: A package for medical image anlaysis The dcemriS4 package is a major update, and S4 implementation, of the dcemri package.? All previous functionality has been replicated, for DCE-MRI and DWI, with specific emphasis on cancer imaging applications.? Additional major features include: ? o S4 classes for NIfTI and Analyze data formats that merges header and data information o

The first release of "RNiftyReg", an R package for registration (alignment and resampling) of medical images, is now available on CRAN [1]. It may also be useful for other 3D array-like data sets. RNiftyReg is built on top of the NiftyReg library [2], and is written in a mixture of C, C++ and R. It currently supports 3D rigid-body and affine registration, and support for 2D and nonlinear

The first release of "RNiftyReg", an R package for registration (alignment and resampling) of medical images, is now available on CRAN [1]. It may also be useful for other 3D array-like data sets. RNiftyReg is built on top of the NiftyReg library [2], and is written in a mixture of C, C++ and R. It currently supports 3D rigid-body and affine registration, and support for 2D and nonlinear