similar to: frailty in coxph

Dear List, In documents (Therneau, 2003 : On mixed-effect cox models, ...), as far as I came to know, coxme penalize the partial likelihood (Ripatti, Palmgren, 2000) where as frailtyPenal (in frailtypack package) uses the penalized the full likelihood approach (Rondeau et al, 2003). How, then, coxme and coxph(...frailty(id, dist='gauss')) differs? Just the coding algorithm, or in

Dear all, Does the frailty.object$history[[1]]$theta returns the Variance of random effect? Why is the value different? Here is an example with kidney data: > library(survival) > data(kidney) > frailty.object<-coxph(Surv(time, status)~ age + sex + disease + frailty(id), kidney) > frailty.object Call: coxph(formula = Surv(time, status) ~ age + sex + disease + frailty(id), data

Dear R-list users, I am trying to do simulation of survival data to enable it to run under frailty option. Below is the function a that I am using. My questions are: 1. How do I modify it to get bigger (hopefully significant) value of Variance of random effect? 2. What changes do I have to make in the function to run it under correlated frailty model? (may be in kinship package) 3. Is there

Dear List, How do I extract the approximate Wald test for the frailty (in the following example 17.89 value)? What about the P-values, other Chisq, DF, se(coef) and se2? How can they be extracted? ######################################################> kfitm1 Call: coxph(formula = Surv(time, status) ~ age + sex + disease + frailty(id, dist = "gauss"), data = kidney)

Dear all, So far i could do (in an informal way) to draw a Standardized Resisual plot in the following way- --------------------- >x <- c(104.1, 106.6, 105.5, 107.5, 109.6, 113.3, 115.5, 117.7, 119.9, 122.1, 124.3, 126.5, 128.2) >y <- c(53732, 52912, 57005, 61354, 67682, 71602, 71961, 75309, 82931, 93310, 102161, 103068, 108927) >

Dear list, I have been trying to use coxme in R 2.3.1. When I use coxme in the following data sim.fr1, i get "Warning messages: using 'as.environment(NULL)' is deprecated" Why does it occur? How can I hide such warning message, especially when coxme is under a loop? Mohammad Ehsanul Karim (Institute of Statistical Research and Training, University of Dhaka) >

Dear all, Does R or S-plus or any of their packages provide Non-parametric "Run test" (which tests whether a sequence of numbers might be random or not)? If yes, i'd like a numerical illustration of this test. Any response / help / comment / suggestion will be greatly appreciated. Thanks in advance. ------------------------------- Mohammad Ehsanul Karim <wildscop at

Dear all, Does R or S-plus or any of their packages provide any command to form any of the following procedures to find Best Regression Equation - 1. 'All Possible Regressions Procedures' (is there any automated command to perform 2^p regressions and ordering according to criteria R2(adj), mallows Cp, s2- by not setting all the regression models manually), 2. 'Backward

Dear all, I am thinking of writing my own functions in s-plus (or in R). I just know how to work with S-plus / R built-in functions. Therefore, I'm a beginner in S programming. I am looking for some on-line documentation that is well written about "Programming in S language" where control stuctures / loops / vectorization and necessery sequences of S programming are

Dear List, Trying to explain my situation as simply as possible for me: I am running a series of iteration on coxph model on simulated data (newly generated data on each iteration to run under coxph; in my example below- sim.fr is the generated data). However, sometimes i get warning messages like "Ran out of iterations and did not converge" or "Error in var(x, na.rm = na.rm) :

Dear all, Can anyone please help me about any of the following questions: -------------------------------------------- 1. How can i find "factorial" of any number in R? I tried > prod(170:1) # to find factorial of 170 or 170! Is it the only procedure - or R has any better process / operational character to calculate factorial? Also, is it possible to calculate factorial of 500? Or

Dear all, I was wondering if there is any way i could do a "Grid Search" on a parameter space using R (as SAS 6.12 and higher can do it) to start the Newton-Gauss Linearization least squares method when i have NO prior information about the parameter. W. N. Venables and B. D. Ripley (2002) "Modern Applied Statistics with S", 4 th ed., page 216-7 has a topic

Dear List, Suppose, I have some observed and expected frequencies, such as following. I need to draw a graph where plots of observed and expected frequencies are merged into one. ------------------------------------------------ m <- c(1,2,3,4,5,6,7,8,9,10,12,13,17) k <- c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 19) ExpWW <- c(0.309330628803245, 0.213645190887434, 0.147558189649435,

Dear List Members, I need some help about programming in S language. My problem is as follows: I have meteorological data (about rainfall measurement each day from 1989-2002), say like http://www.angelfire.com/ab5/get5/data.rainfall.txt or http://www.angelfire.com/ab5/get5/R.rainfall.txt in a sequence of 0(denoting dry day)'s and 1(denoting wet day)'s. I want to construct a frequency

Dear all, Can any one tell me how can i perform Orthogonal Polynomial Regression parameter estimation in R? -------------------------------------------- Here is an "Orthogonal Polynomial" Regression problem collected from Draper, Smith(1981), page 269. Note that only value of alpha0 (intercept term) and signs of each estimate match with the result obtained from coef(orth.fit). What

Dear List, In R we can plot multiple graphs in same page using par(mfrow = c(*,*)). In each plot we can set title using main and sub commands. However, is there any way that we can place an universal title above the set of plots placed in the same page (not individual plot titles, all i need is a title of the whole graph page) as well as sib-titles? Do I need any package to do so? Thank you

Dear List, Can anyone please explain the difference between cluster() and frailty() in a coxph? I am a bit puzzled about it. Would appreciate any useful reference or direction. cheers, Ehsan > marginal.model <- coxph(Surv(time, status) ~ rx + cluster(litter), rats) > frailty.model <- coxph(Surv(time, status) ~ rx + frailty(litter), rats) > marginal.model Call: coxph(formula =

Dear all, First of all - thanks to the R-users who replied my previous mail "Selecting Best Regression Equation". However, seems i've got some other problems now - My data in c:\leafbrn.txt file is- -------------------------------------- i x1 x2 x3 y 1 3.05 1.45 5.67 0.34 2 4.22 1.35 4.86 0.11 3 3.34 0.26 4.19 0.38 4 3.77 0.23 4.42 0.68 5 3.52 1.10 3.17 0.18 6 3.54 0.76 2.76

Dear all, For estimating Cobb-Douglad production Function [ Y = ALPHA * (L^(BETA1)) * (K^(BETA2)) ], i want to use nls function (without linearizing it). But how can i get initial values? ------------------------------------ > options(prompt=" R> " ) R> Y <- c(59.6, 63.9, 73.5, 75.6, 77.3, 82.8, 83.6, 84.9, 90.3, 80.5, 73.5, 60.3, 58.2, 64.4, 75.4, 85, 92.7, 85.4,

Hello, I was hoping that someone could answer a few questions for me (the background is given below): 1) Can the coxph accept an interaction between a covariate and a frailty term 2) If so, is it possible to a) test the model in which the covariate and the frailty appear as main terms using the penalized likelihood (for gaussian/t frailties) b)augment model 1) by stratifying on the variable that