search for: ruwanthi

...ions.cfm to R. Once save this file to C:\, how I could load into R? I am working in Windows XP. Usually what I do is, I go to "packages" and then "install packages from local zip files". This procedure fails for .tar.gz files. Can someone help here please.... Thanks very much. Ruwanthi

... illness (0-worse, 1-same, 2-better). So, longitudinal response is categorical.  I was wondering whether lmer in R can fit a model for this type of data. If so, how we code? Or any other function in R that can fit this type of longitudinal data? Any suggestion would be greatly appreciated.   Thanks Ruwanthi   [[alternative HTML version deleted]]

Dear list   I have 5 markers that can be used to detect an infection in combination. Could you please advise me how to use functions in ROCR/ other package to produce the ROC curve for a combination of markers?   I have used the following to get ROC statistics for each marker. pred <- prediction(y$marker1, y$infectn) perf <-performance(pred,"tpr","fpr")

...(Surv(time,status) ~ as.factor(treat), data=dat1,random= ~1|group,varlist=list(mat1,mat2),rescale=F,pdcheck=FALSE) Error in coxme.fit(X, Y, strats, offset, init, control, weights = weights, : Random effects variance is not spd Could anyone help me correcting this error? Many thanks in advance. Ruwanthi ____________________________________________________________________________________ Looking for last minute shopping deals?

...,failcode=1,cencode=0) where agesplit is defined as <20,21-29,>30 years, so it takes 0, 1 or 2 for each patient. I hoped to get estimated coefficients for the levels 1 and 2 w.r.t level 0 as in coxph. But, I didn't. Could someone please help me to use crr in this situation? Thanks a lot. Ruwanthi

Dear R users,   I want to compute the 95% CI for difference in median survival times of two treatment groups. survfit function in R gives median and the corresponding CIs for each group. Could you please help me to get a CI for the difference in median times?   Thanks Ruwanthi [[alternative HTML version deleted]]

Dear List,   I am new to ROC analysis and the package ROCR. I want to compute the confidence intervals of sensitivity and specificity for a given cutoff value. I have used the following to calculate sensitivity and specificity:   data(ROCR.simple) pred <- prediction(ROCR.simple$predictions, ROCR.simple$labels)   se.sp <- function (cutoff, performance) {     sens <-

Hi   I am using following code to produce a xyplot for some longitudinal data. There are 2 panels. It produced all longitudinal trajectories with mean profile. But since the dataset it very large plot looks very messy. I want to show, say 10 randomly selected individual longitudinal trajectories together with mean profile for entire dataset. Could any help me to alter the following code to do