[R] half-logistic distribution

[Therneau, Terry M., Ph.D.]

On 12/26/2014 05:00 AM, r-help-request at r-project.org wrote:
> i want to analyse survival data using typeI HALF LOGISTIC
> DISTRIBUTION.how can i go about it?it installed one on R in the
> survival package didn't include the distribution...or i need a code to
> use maximum likelihood to estimate the parameter in survival
> analysis.a typical example of distribution other than that installed
> in R will help.thanks
>

I am the author of the survival package, and had never heard of the "type I half-logistic" 
before.
New distributions can be added to survreg() if they can be represented as location-scale 
families; I don't think that your distribution can be written in that way.

Look at "survival" under the "Task Views" tab (upper left corner) of the cran.org web page 
-- someone else may have already done it.

Terry T.