Dear r-help subscribers, A couple of weeks ago I sent the following message to the r-help mail list. It hasn't generated any response, and I could really use some help on this. Anyone able to help? Thanks again, Roger Dungan>>I am working on some survival analysis of some interval censored failure time data in R. I have done similar analysis before using PROC LIFEREG in SAS. In that instance, a gamma survival function was the optimum parametric model for describing the survival and hazard functions. I would like to be able to use a gamma function in R, but apparently the survival package does not support this distribution. I have been googling around for some help, and have found some threads to a similar question posted to the R-Help list in October last year. Because I am a bit of a survival analysis and R newbie, I didn't really understand the discussion thread. I've been working with a Weibull distribution, thus:>leafsurv.weibull<-survreg(Surv(minage, maxage, censorcode, type >"interval")~1, dist = "weib")And I guess I'd like to be able to do something that's the equivalent of>leafsurv.gamma<-survreg(Surv(minage, maxage, censorcode, type = >"interval")~1, dist = "gamma")At least one of the R-help listserver comments mentioned using survreg.distributions to customise a gamma distribution, but I can't figure out how to make this work with the resources (intellectual and bibliographical!) that I have available. With thanks in advance for your help, Dr Roger Dungan School of Biological Sciences University of Cantebury Christchurch, New Zealand ph +64 3 366 7001 ext. 4848 fax +64 3 354 2590
Google for the gfcure package on statlib. I have not used it myself and am not entirely sure whether it works on R or just S. Roger Dungan <roger.dungan <at> canterbury.ac.nz> writes: : : Dear r-help subscribers, : : A couple of weeks ago I sent the following message to the r-help mail : list. It hasn't generated any response, and I could really use some help : on this. Anyone able to help? : : Thanks again, : : Roger Dungan : : >> : I am working on some survival analysis of some interval censored failure : time data in R. I have done similar analysis before using PROC LIFEREG : in SAS. In that instance, a gamma survival function was the optimum : parametric model for describing the survival and hazard functions. I : would like to be able to use a gamma function in R, but apparently the : survival package does not support this distribution. I have been : googling around for some help, and have found some threads to a similar : question posted to the R-Help list in October last year. Because I am a : bit of a survival analysis and R newbie, I didn't really understand the : discussion thread. : : I've been working with a Weibull distribution, thus: : : >leafsurv.weibull<-survreg(Surv(minage, maxage, censorcode, type : >"interval")~1, dist = "weib") : : And I guess I'd like to be able to do something that's the equivalent of : : >leafsurv.gamma<-survreg(Surv(minage, maxage, censorcode, type = : >"interval")~1, dist = "gamma") : : At least one of the R-help listserver comments mentioned using : survreg.distributions to customise a gamma distribution, but I can't : figure out how to make this work with the resources (intellectual and : bibliographical!) that I have available. : : With thanks in advance for your help, : : Dr Roger Dungan : School of Biological Sciences : University of Cantebury : Christchurch, New Zealand : ph +64 3 366 7001 ext. 4848 : fax +64 3 354 2590 : : ______________________________________________ : R-help <at> stat.math.ethz.ch mailing list : https://stat.ethz.ch/mailman/listinfo/r-help : PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html : :
On Thu, 24 Feb 2005, Roger Dungan wrote:> Dear r-help subscribers, > > A couple of weeks ago I sent the following message to the r-help mail > list. It hasn't generated any response, and I could really use some help > on this. Anyone able to help? >You can't easily fit a gamma distribution with survreg() unless it has known shape parameter. survreg() fits location-scale models, optionally with log transformation, and the gamma family is not one of these. -thomas> Thanks again, > > Roger Dungan > >>> > I am working on some survival analysis of some interval censored failure > time data in R. I have done similar analysis before using PROC LIFEREG > in SAS. In that instance, a gamma survival function was the optimum > parametric model for describing the survival and hazard functions. I > would like to be able to use a gamma function in R, but apparently the > survival package does not support this distribution. I have been > googling around for some help, and have found some threads to a similar > question posted to the R-Help list in October last year. Because I am a > bit of a survival analysis and R newbie, I didn't really understand the > discussion thread. > > I've been working with a Weibull distribution, thus: > >> leafsurv.weibull<-survreg(Surv(minage, maxage, censorcode, type >> "interval")~1, dist = "weib") > > And I guess I'd like to be able to do something that's the equivalent of > >> leafsurv.gamma<-survreg(Surv(minage, maxage, censorcode, type >> "interval")~1, dist = "gamma") > > At least one of the R-help listserver comments mentioned using > survreg.distributions to customise a gamma distribution, but I can't > figure out how to make this work with the resources (intellectual and > bibliographical!) that I have available. > > With thanks in advance for your help, > > Dr Roger Dungan > School of Biological Sciences > University of Cantebury > Christchurch, New Zealand > ph +64 3 366 7001 ext. 4848 > fax +64 3 354 2590 > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html >Thomas Lumley Assoc. Professor, Biostatistics tlumley at u.washington.edu University of Washington, Seattle