similar to: Gompertz-Makeham hazard models---test for significant difference

Hi all, Sorry if this has been answered already, but I couldn't find it in the archives or general internet. Is it possible to implement the gompertz distribution as survreg.distribution to use with survreg of the survival library? I haven't found anything and recent attempts from my side weren't succefull so far. I know that other packages like 'eha' and

Dear Sir/ Madam, I'm having trouble de-bugging the following - which works perfectly well with optim or optimx - but not with mle2. I'd be really grateful if someone could show me what is wrong. Many thanks in advance. JSC: gompertz<- function (x,t=data) { a3<-x[1] b3<-x[2] shift<-data[1] h.t<-a3*exp(b3*(t-shift))

Dear list: I am attempting to use what I thought would be a pretty straightforward practical application of Cox regression. I figure users of the survival package must have come across this problem before, so I would like to ask you how you dealt with it. I have set up an illustrative example and included it at the end of this post. I took a sample of 100 data points from each of two populations

Hello, all. I have co-opted a number of functions that can be used to plot the hazard/survival functions and associated density distribution for a Gompertz mortality model, given known parameters. The Gompertz hazard model has been shown to fit relatively well to the human adult lifespan. For example, if I wanted to plot the hazard (i.e., mortality) functions: pop1 <- function (t) {

Dear R listers, I have a data file looks like the following: Testing marker: s_1 --------------------------------------------- Allele df(0) -LnLk(0) df(T) -LnLk(T) ChiSq p 3 7995 29320.30 7994 29311.85 16.90 4e-05 (2229/8000 probands) Testing marker: s_2 --------------------------------------------- Allele df(0)

Full_Name: Lyle W. Konigsberg Version: 1.5.1 OS: Windows Submission from: (NULL) (160.36.64.99) I apparently found an error in how "deriv" puts a derivative to the screen (though the internal representation is correct). Here's what I was doing for a class example: > lnlk<-expression(15*log(p)+11*log(1-p)) > p<-15/26 > D(D(lnlk,"p"),"p") -15 *

Hello. I am trying to write an R function to plot the survival function (and associated hazard and density) for a Siler competing hazards model. This model is similar to the Gompertz-Makeham, with the addition of a juvenile component that includes two parameters---one that describes the initial infant mortality rate, and a negative exponential that describes typical mortality decline over the

Hi, r-help members. I have a question about summing two density distributions. I have two samples from which I've estimated hazard parameters for a Gompertz mortality model. With those parameters, I can calculate the PDF (survival function times hazard function) of ages-at-death in a birth cohort subject to the hazard function at each age. I'd like to combine these two density

I haven't used r in quite a while but would like to get back into it. I have a problem that I would like to solve with r. I have some multinomial data that looks to follow an asymmetric sigmoidal growth pattern. Solving a multinomial gompertz partial differential equation in r is what I’m after. Would anyone be able to provide me the code and packages to do something like this? Regards,

Hi, I build a graph taking into account the times: 1, 2,4,6,8,10,12,15,18,21,24,28,32 and 48. Be that the scale of the X axis does not look right. It seems equidistant. (graph attached) What changes have I to do in the following commands so that the scale be correct? interaction.plot(Tempo, Trat, Valor, ylim=c(0, 2), las=1, lty=c(1,2,3,4), lwd=3, bty='l',

Dear all! I tried to fit Gompertz growth models to describe cummulative germination rates using nls. I used the following code: germ.model<-nls(percent.germ~a*exp(-b*exp(-k*day)),data=tab,start=list(a=100,b=10,k=0.5)) My problem is that I want that the fitted model goes through the origin, since germination cannot start before the experiment was started, and y-max should be 100. Does anyone

I feel like a complete dolt, as I know this question has been asked by others on a fairly regular basis, but I'm going in circles trying to get the following to work: id.prob<-function (tt) { library(mvtnorm) #============================ Makeham<-function(tt) { a2=0.030386513 a3=0.006688287 b3=0.039047537 t<-tt-20 h.t<-a2+a3*exp(b3*t) S.t<-exp(-a2*t+a3/b3*(1-exp(b3*t)))

Hi I have put together dovecot port for the OpenBSD ports system. The port has yet to be submitted, but is finished awaiting testing from a wider audience. I have been using dovecot successfully on OpenBSD/sparc64 -current for months now with no problems. Would you recommend including the CR+LF patch? http://cemetery.homeunix.org/OpenBSD/dovecot.tar.gz -- http://cemetery.homeunix.org

On Apr 12, 2007, at 12:57 PM, Michael McCracken wrote: > Hi, the idea of a dragon theme reminded me of the dragon-like serpents > called "Nāga" from Cambodian mythology, among other places. Interesting, my only comment is if we pick this we need to just spell it Naga. Naga are also snake people in D&D (yea... I know). > > Here's a brief link explaining the

Dear All, I would like to fit some parametric survival models using left truncated, right censored data in R. However I am having problems finding a function to fit parametric survival models which can handle left truncated data. I have tested both the survreg function in package survival: fit1 <- survreg(Surv(start, stop, status) ~ X + Y + Z, data=data1) and the psm function in package

Dear R Help team, I'm having some problems running a discriminant analysis (MASS:lda) over my data, i have a grouping variable coming from a previous cluster analysis and several discriminators (78 actually). I'm trying to run lda using column index as independent variable in the formula like it's done in the help page for ?formula:

Hey All, Sometimes we are running into issues with calls randomly being disconnected. We have a couple of phones is in a remote office. We have a PIX-to-PIX VPN setup between the offices. I know neither of these devices provide QOS but we usually don't run into any problems. I notice this problem when we are in a conference call with one of the employees at the remote office and a

Hiya builds fine on BSD now (thanks) Now I am getting index corruption again May 30 03:11:53 snigger imap(bob): Corrupted binary tree file /home/bob/Mail/.INBOX/.imap.index.tree: UID to be inserted isn't higher than existing (1 <= 1) and so on until the client hangs test7 is stable here. Also what are the correct permissions for /var/run/dovecot/login? I get a message about correcting

Hi, I wanted to know how do we set the bitrates for the speex encoder through the program . I want to assign various bitrates and chk the encoding at those rates. Thanks and Regards Naga Praveen N -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20060516/6aada638/attachment.html

On Apr 12, 2007, at 10:57 AM, Michael McCracken wrote: > Hi, the idea of a dragon theme reminded me of the dragon-like serpents > called "Nāga" from Cambodian mythology, among other places. naga.org already exists, though. We probably want to have the .org available. I like the dragon theme but most of the familiar dragon names are taken. The Hydra of Greek mythology was a