similar to: Exponential, Weibull and log-logistic distributions in glm()

Dear R-users I have some datasets, all left-censoring, and I would like to fit distributions to (weibull,exponential, etc..). I read one solution using the function survreg in the survival package. i.e survreg(Surv(...)~1, dist="weibull") but it returns only the scale parameter. Does anyone know how to successfully fit the exponential, weibull etc... distributions to left-censoring

Dear All, I have two questions regarding distribution fitting. I have several datasets, all left-truncated at x=1, that I am attempting to fit distributions to (lognormal, weibull and exponential). I had been using fitdistr in the MASS package as follows: fitdistr<-(x,"weibull") However, this does not take into consideration the truncation at x=1. I read another posting in this

I unintentionally missed to cc to r-devel. -------- Original Message -------- Subject: Re: [Rd] levels for list and data.frame Date: Tue, 21 Mar 2006 20:50:21 +0100 From: Gregor Gorjanc <gregor.gorjanc at gmail.com> Reply-To: gregor.gorjanc at gmail.com To: Martin Maechler <maechler at stat.math.ethz.ch> References: <441F2C49.8080703 at gmail.com> <17439.50351.172900.987055

Duncan, you are a king! Thanks a lot for this cookie. It really helped me. Thanks for the code as well as detailed explanation at the end. >Hi Gregor. > >Here is a function that will collect all of the nodes in the >XML document whose names are in the vector elementNames > >getElements = >function(elementNames) >{ > els = list() > > startElement = function(node,

James, thanks for the response. I understand now my puzzle. tmp <- data.frame(y1=1:4, f1=factor(c("A", "B", "C", "D"))) tmp$y2 <- NA tmp[1:2, "y2"] <- 2 Does the job. I see that I should add a full column. In my case adding full column of NAs and then adding values, solves my problems. Thanks to all. james.holtman at convergys.com

I was wondering if someone familiar with survival analysis can help me with the following. I would like to fit a Weibull curve, that may be dependent on a covariate, my dataframe "labdata" that has the fields "cov", "time", and "censor". Do I do the following? wieb<-survreg(Surv(labdata$time, labadata$censor)~labdata$cov,

Hi all I try to make a weibull survival analysis on R. I know make this on GLIM, and now I try to make the GLIM exercice GLEX8 on R to learning and compare the test. The variables are: time censor group bodymass In GLIM I make: $calc %s=1 $ to fit weibull rather than exponential $input %pcl weibull $ $macro model group*bodymass $endmac$ $use weibull t w %s $ Then, GLIM estimate an alpha for the

Hello, I'm quite new to R and want to make a Weibull-regression with the survival package. I know how to build my "Surv"-object and how to make a standard-weibull regression with "survreg". However, I want to fit a translated or 3-parametric weibull dist to account for a failure-free time. I think I would need a new object in survreg.distributions, but I don't know how

Hello! I have a matrix with data and a column indicating whether it is censored or not. Is there a way to apply weibull and exponential maximum likelihood estimation directly on the censored data, like in the paper: Backtesting Value-at-Risk: A Duration-Based Approach, P Chrisoffersen and D Pelletier (October 2003) page 8? The problem is that if I type out the code as below the likelihood

I am trying to generate predictions from a weibull survival curve but it seems that the predictions assume that the shape(scale for survfit) parameter is one(Exponential but with a strange rate estimate?). Here is an examle of the problem, the smaller the shape is the worse the discrepancy. ### Set Parameters scale<-10 shape<-.85 ### Find Mean scale*gamma(1 + 1/shape) ### Simulate Data

Jun hi again! Sorry for bothering. Although I had no problem with building Windows package under Linux, I noticed that man pages are not processed as they should or maybe I have a problem with my setup. My package is called 'GeneticsPed'. Instead of HTML or text files I just got a GeneticsPed.Rd.gz in man directory of a package (this is within GeneticsPed_0.1.zip file!). The file

Hello to Rusers! I am puzzled with R and I really do not know where to look in for my problem. I am moving from SAS and I have difficulties in translating SAS to R world. I hope I will get some hints or pointers so I can study from there on. I would like to do something like this. In SAS I can write a macro as example bellow, which is afcourse a silly one but shows what I don't know how

Dear R-users I would like to fit weibull parameters using "Method of moments" in order to provide the inital values of the parameter to de function 'fitdistr' . I don`t have much experience with maths and I don't know how to do it. Can anyone please put me in the rigth direction? Borja [[alternative HTML version deleted]]

On 12 October 2006 at 13:02, Gregor Gorjanc wrote: | Hello! | | I encounter the following problem when I try to load package foreign | | library(foreign) | Error in dyn.load(x, as.logical(local), as.logical(now)) : | unable to load shared library '/usr/lib/R/library/foreign/libs/foreign.so': | /usr/lib/R/library/foreign/libs/foreign.so: undefined symbol: | Rf_allocString | Error:

Dear R users, I'm trying to fit a parametric survival model using the survreg function with a Weibull distribution. I'm studying the time to death of individuals from different families and I would like to fit different shape parameters (ie 1/scale in R) for each of the families. I looked it up in the help pdf and on the internet, but I couldn't find anything. Would it be possible to

Hello R users! I just found out that I have 49 invitations for Gmail (gmail.google.com). I have been using it now for a while and is really nice. Don't forget 1 GB for free. I will invite those who respond to this mail by FIFO. -- Lep pozdrav / With regards, Gregor Gorjanc ------------------------------------------------------------------------ University of Ljubljana Biotechnical

Hello! Is it possible to set na.rm=TRUE in a global way? I'am constantly forgeting on this when performing analyses. I agree that one should be carefull with this when developing some code, but not necesarilly so in data analysis. Lep pozdrav / With regards, Gregor Gorjanc ---------------------------------------------------------------------- University of Ljubljana PhD student

Hello! I am crossposting this to R-help and BioC, since it is relevant to both groups. I wrote a wrapper for Entrez search utility (link for this is provided bellow), which can add some new search functionality to existing code in Bioconductor's package 'annotate'*. http://eutils.ncbi.nlm.nih.gov/entrez/query/static/esearch_help.html Entrez search utuility returns a XML document

And a last post from Paul Gilbert. Thanks to all! This disscusion was really beneficial for me! -----Original Message----- From: Paul Gilbert [mailto:pgilbert at bank-banque-canada.ca] Sent: sre 2005-06-08 21:01 To: Gorjanc Gregor Subject: Re: [R] Random seed problem in MCMC coupling of chains Gorjanc Gregor wrote: > Thanks to Paul and Gabor for additional tips/examples. Actually, I find

Hello! I have a continous distribution and would like to get mode (the most frequent value in distribution). I easily found mean, median and other basic thing but not mode function. Can anyone help? I know there my might be problems with multiple modes, but still I think that there should be a mode function in R. Please send mail to R-help list and me, so I can get response faster. Thank