similar to: Proportional hazard model with weibull baseline hazard

Assume that we collect below data : - subjects = 20 males + 20 females, every single individual is independence, and difference events = 1, 2, 3... n covariates = 4 blood types A, B, AB, O http://r.789695.n4.nabble.com/file/n4245397/CodeCogsEqn.jpeg ?m = hazards rates for male ?n = hazards rates for female Wm = Wn x ?, frailty for males, where ? is the edge ratio of male compare to female Wn =

Dear all, I think the coxph and survfit.coxph can give the cumulative hazard of cox model. But is there any method to calculate the hazard Lambda(t)=lambda_0(t)*exp{beta*X(t)}? Any suggestion will be great help. Thank you very much! Koshihaku -- View this message in context: http://r.789695.n4.nabble.com/How-to-get-the-hazard-of-coxph-not-cumulative-hazard-tp3873516p3873516.html Sent from the R

Hi, I would like to compare the hazard functions of two samples using the Cox proportional hazards model. For sample 1 I have individual time-to- event data. For sample 2 I don't have individual data, but grouped data that allows to obtain a hazard function. I am wondering if there is an R function that allows to obtain a hazard ratio of the two hazard funtions (under the

Dear Sir/Madam, I apologize for any cross-posting. I got a simple question, which I thought the R list may help me to find an answer. Suppose we have Y_1, Y_2, ., Y_n ~ Poisson (Lambda_i) and Lambda_i ~Gamma(alpha_i, beta_i). Empirical Bayes Estimator for hyper-parameters of the gamma distr, i.e. (alpha_t, beta_t) are needed. y=c(12,5,17,14) n=4 What about a Hierarchal B ayes

Please help, I tried a program on S-plus, and it worked. Also I tried the same program on R but not worked. Here is the programme. I put it in a function form. The model and assumption are at the bottom. where counts<-c(22,2,2,0,5,7,14,0,0,2,36,0,0,1,17,10) which is name.data, i is row size and j is the column size. symmetry function(i, j, name.data) { row <- (c(1:i)) col <-

I have data on a number of patients. Essentially, for each patient I know his/her age and whether he/she exhibits certain symptoms: age symptom1 symptom2 50 0 1 53 0 0 70 1 1 ... I have started off by fitting simple models with forms like Prob(patient of age t shows symptom i) = 1 - Exp(-lambda_i * t) or Prob(patient of age t shows

Hi, has anyone ever seen implemented in R the following "geodesic" distance between positive definite pxp matrices A and B? d(A,B) = \sum_{i=1}^p (\log \lambda_i)^2 were \lambda is the solution of det(A -\lambda B) = 0 thanks stefano

Hi, Given a positive integer N, and a real number \lambda such that 0 < \lambda < 1, I would like to generate an N by N stochastic matrix (a matrix with all the rows summing to 1), such that it has the second largest eigenvalue equal to \lambda (Note: the dominant eigenvalue of a stochastic matrix is 1). I don't care what the other eigenvalues are. The second eigenvalue is

Hi, If I set df=2 in my smooth.spline function, is that equivalent to running a linear regression through my data? It appears that df=# of data points gives the interpolating spline and that df = 2 gives the linear regression, but I just want to confirm this. Thank you, Steven

Hi, I would like to know whether there exist algorithms to compute the coefficients or, at least, the degree of the minimal polynomial of a square matrix A (over the field of complex numbers)? I don't know whether this would require symbolic computation. If not, has any of the algorithms been implemented in R? Thanks very much, Ravi. P.S. Just for the sake of completeness, a

Dear R-listers, I want to reperfrom a poisson distribution test that presented in a recent-published biological research paper (Plant Physiology 2008, vol 148, pp. 1189-1200). That test is about the occurrence number of a kind of gene in separate chromosomes. For instance: The observed gene number in chromosome A is 36. The expected gene number in chromosome A is 30. Then, the authors got a

For example, PcaHubert, how to get the variance explained which are similar to those concepts in traditional PCA? In traditional PCA, you have a bunch of eigenvalue lambdas... and you sort the lambdas from the biggest to the smallest, the lambda_i / (sum of all lambdas) is the variance explained by that principal component... how to obtain the equivalent concepts in PcaHubert? Thanks a lot!

Hi, I''ve not been able to get clean runs on this testsuite with snv_130+ bits, nor with snv_130. Would appreciate a pointer to snv_130 baseline results. thnks, -oscar

Greetings -- I would like to estimate a proportional hazard model with a weibull or lognormal baseline. I have looked at both the coxph() and survreg() functions and neither appear (to me ) to do it. Am I missing something in the docs or is there another terrific package out there that will do this. Many Thanks. Carl Mason

Hi, If I fit a Cox model using "coxph", is there a R function so that I could obtain the estimate of baseline survival function? Thank you. Zheng -- Zheng Yuan Ph.D student Department of Biostatistics University of Michigan Ann Arbor, MI 48109

? Hallo, which function can i use to do (baseline) logistic regression + goodness of fit tests? so far i found: # logistic on binary data lrm combined with resid(model,'gof') # logistic on binary data glm with no gof-test # baseline logit on binary data

Dear R-help, I am trying to obtain the baseline survival estimate of a fitted Cox model (S_0 (t)). I know that previous posts have said use 'basehaz' but this gives the baseline hazard function and not the baseline survival estimate. Is there a way to obtain the baseline survival estimate or do I have to use the formula which does something like S(t) = exp[- the integral from 0 to t of

Hello everyone, I want to fit a baseline category logit model (with 3-4 categories) with nested random effects. (For example, I have clusters(i) and households within clusters (j) resulting in the nested random effects structure : b_i +d_j(i)). Is there a R function/package that I can use ? Any help will be much appreciated. Thanks and regards, Dhiman Bhadra [[alternative HTML version

Hi, assume that I have a repeated measure dataset with 3 time points: baseline, day 5 and day 10. There are 4 treatment groups (vehicle, treatment 1, treatment 2 and treatment 3). 20 subjects per treatment group. A simple straight-forward way to analyze the data is to use mixed model: model 1: obj <- lmer(y ~ treatment * time +(time|subject)) where time is numeric with value 0,5 and 10.

Dear colleagues, I have the following dataset. It is modelled on the data included in Box-Seteffenheiser and Jones "Event History Modelling" Using the following code, I try to find the baseline hazard function haz_1<-muhaz(bpa$time, bpa$censored, subset=(bpa$year=="2010" | bpa$ban=="1"), min.time=1, max.time=3) I think I'm doing everything right, but what I