search for: hazard

Displaying 20 results from an estimated 983 matches for "hazard".

2012 Jul 06
1
How to compute hazard function using coxph.object
My question is, how to compute hazard function(H(t)) after building the coxph model. I even aware of the terminology that differs from hazard function(H(t)) and the hazard rate(h(t)). Here onward I wish to calculate both. Here what I have done in two different methods; ###############################################################...
2008 Apr 09
2
How to estimate a hazard ratio using an external hazard function
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 ha...
2006 Jul 07
6
parametric proportional hazard regression
Dear all, I am trying to find a suitable R-function for parametric proportional hazard regressions. The package survival contains the coxph() function which performs a Cox regression which leaves the base hazard unspecified, i.e. it is a semi-parametric method. The package Design contains the function pphsm() which is good for parametric proportional hazard regressions when the under...
2011 Feb 10
2
[LLVMdev] Hazard recognizers & basic blocks
I am working on a target which has some structural hazards. To detect these hazards, I implemented a sub-class of PostRAHazardRecognizer. PostRAHazardRecognizer resets the hazard state on a basic block basis. So, how to detect hazards that may occur between the end of a basic block and the beginning of another basic block ? Thanks ! --------------...
2007 Dec 18
1
hazard ratio of interaction Cox model
Dear Forum, I have a question about interaction estimate in the Cox model: why the hazard ratio of the interaction is not produced in the summary of the model? (Instead, the estimate of the coefficient is given in the print of the model.) # Example: modINT <-cph( Surv(T_BASE, T_FIN,STATUS)~ NYHA + ASINI + RFP + FE_REC + XX_PR*XX_DISF) print(modINT) coef se(co...
2003 Jul 11
2
hazard estimate
Dear list, is there a function available which provides an estimate of the hazard function based on a cox proportional hazard model? I only found the cumulative hazard and the survival function as survfit options. Thanks for your help Peter
2013 Sep 22
2
[LLVMdev] how to detect data hazard in pre-RA-sched
hi, LLVM, I found there is a flag DisableHazardRecognizer in TargetInstrImpl.cpp. I still don't understand how llvm detects data hazard in pre-RA-sched. pre-RA-sched is based on SDNode and all operands are vregs. Even you can calculate the operators of SDNodes, the data hazard in vreg are not same as physical register data hazard. Is it usef...
2005 Jun 10
1
Estimate of baseline hazard in survival
Dear All, I'm having just a little terminology problem, relating the language used in the Hosmer and Lemeshow text on Applied Survival Analysis to that of the help that comes with the survival package. I am trying to back out the values for the baseline hazard, h_o(t_i), for each event time or observation time. Now survfit(fit)$surv gives me the value of the survival function, S(t_i|X_i,B), using mean values of the covariates and the coxph() object provides me with the estimate of the linear predictors, exp(X'B). If S(t_i|X_i,B)=S_o(t_i)^exp(X_iB) i...
2013 Sep 24
0
[LLVMdev] how to detect data hazard in pre-RA-sched
On Sep 21, 2013, at 8:02 PM, Liu Xin <navy.xliu at gmail.com> wrote: > hi, LLVM, > > I found there is a flag DisableHazardRecognizer in TargetInstrImpl.cpp. I still don't understand how llvm detects data hazard in pre-RA-sched. pre-RA-sched is based on SDNode and all operands are vregs. Even you can calculate the operators of SDNodes, the data hazard in vreg are not same as physical register data hazard. Is it usef...
2010 Nov 25
1
How to change value of y axis from log relative Hazard to relative Hazard
...r=TRUE) attach(A) rcspline.plot(factor,Time,model="cox",xrange=c(0,3),ylim=c(-1,2),event=event,nk=4,knots=c(0.8,1.0,1.5,2.0),showknots=TRUE,plotcl=FALSE,statloc="none",subset=SEX=="2",lty=2) The plot could be made but its y axis represents the value of log relative Hazard, is there any method to change value of y axis from log relative Hazard to relative Hazard? Millions of thanks! -- View this message in context: http://r.789695.n4.nabble.com/How-to-change-value-of-y-axis-from-log-relative-Hazard-to-relative-Hazard-tp3058505p3058505.html Sent from the R help m...
2006 Feb 27
1
Different deviance residuals in a (similar?!?) glm example
...hem is given at the end). The following example tried to be as completed as possible and I hope that it will be clearer than my previous words. Thanks, Carlo Giovanni Camarda #### simulation procedure age <- 50:100 # time range # parameters alpha.sim <- 0.00005 beta.sim <- 0.1 # simulated hazard from a Gompertz hazard.sim <- alpha.sim*(exp(beta.sim*age)) # first dataset exposures <- c(4748, 4461, 4473, 4326, 4259, 4219, 4049, 3965, 3801, 3818, 3670, 3521, 3537, 3482, 3347, 3180, 3100, 2890, 2755, 2622, 2530, 2502, 2293, 2216, 1986, 1875, 1693, 1550, 13...
2005 Mar 21
2
Hazard function or cumulative Hazard function in R
Hi, I'm student from canada, and i'work in survival analysis.I want to know if there is a hazard function or cumulative hazard function in R or not, i know how to program it, but it is easy to use it if they exists in R. Thanks. Yassir
2010 Nov 15
1
Proportional hazard model with weibull baseline hazard
Dear R-users, I would like to fit a fully parametric proportional hazard model with a weibull baseline hazard and a logit link function. This is, the hazard function is: lambda_i (t) = lambda_0 (t) psi (x_i* beta) where lambda_0 is a weibull distribution and psi a logistic distribution. Does someone know a package and/or function on R to do this? Thanks. -- M.L. Aven...
2011 Oct 06
1
non-cumulative hazard in Cox model with time-dependent covariates
Dear all, Is there a way to calculate the non-cumulative hazard (instantaneous hazard), which is the product of baseline hazard and exp{beta*covariate} ? I knew in survfit, we can get the estimator of cumulative baseline hazard, but how can we get the non-cumulative one? Thank you very much! Koshihaku -- View this message in context: http://r.789695.n4.nabbl...
2006 Mar 07
1
breslow estimator for cumulative hazard function
Dear R-users, I am checking the proportional hazard assumption of a cox model for a given covariate, let say Z1, after adjusting for other relavent covariates in the model. To this end, I fitted cox model stratified on the discrete values of Z1 and try to get beslow estimator for the baseline cumulative hazard function (H(t)) in each stratum. As fa...
2011 Dec 10
2
p-value for hazard ratio in Cox proportional hazards regression?
Hi, I'm new to R and using it for Cox survival analysis. Thanks to this great forum I learned how to compute the HR with its confidence interval. My question would be: Is there any way to get the p-value for a hazard ratio in addition to the confidence interval? Thanks, Thierry -- Thierry Panje Visiting Student Researcher Department of Psychology Stanford Psychophysiology Lab 450 Serra Mall, Bldg 420 Stanford University
2011 Feb 13
0
[LLVMdev] Hazard recognizers & basic blocks
Ooops, you are right. Just forgot to CC the mailing list. Thanks for noticing it,, -- Arnaud de Grandmaison ________________________________________ From: Damien Vincent [damien.llvm at gmail.com] Sent: Saturday, February 12, 2011 3:57 AM To: Arnaud Allard de Grandmaison Subject: Re: [LLVMdev] Hazard recognizers & basic blocks Merci ! I was also planning to add a second pass to verify these special cases but wanted to make sure there is not a simpler and consistent way before proceeding. And you're right, another way is also to make sure that the final or the first instruction of a ba...
2010 Nov 16
1
Re : interpretation of coefficients in survreg AND obtaining the hazard function for an individual given a set of predictors
Thanks for sharing the questions and responses! Is it possible to appreciate how much the coefficients matter in one or the other model? Say, using Biau's example, using coxph, as.factor(grade2 == "high")TRUE gives hazard ratio 1.27 (rounded). As clinician I can grasp this HR as 27% relative increase. I can relate with other published results. With survreg the Weibull model gives a coefficient -0.4035245: is it feasible or meaningful to translate it to HR? Thanks in advance, Vincent Vinh-Hung Radiation Oncology, G...
2009 Jun 20
1
Plotting Cumulative Hazard Functions with Strata
Hello: So i've fit a hazard function to a set of data using kmfit<-survfit(Surv(int, event)~factor(cohort)) this factor variable, "cohort" has four levels so naturally the strata variable has 4 values. I can use this data to estimate the hazard rate haz<-n.event/n.risk and calculate the cumulative hazard f...
2009 Mar 14
1
obtaining the values for the hazard function in a cox regression
Hello , I am hoping for some advice regarding obtaining the values for the hazard function in a cox regression that I have undertaken. I have a model in the following form, analysed with the package survival (v. 2.34-1) and a log-log plot obtained using Design (v. 2.1-2). For two variables, the lines in the survival curves crossed. The statistician I been obtaining advice fr...