From tim@timcohn.com  Wed Nov 13 22:05:22 2002
From: tim@timcohn.com (tim@timcohn.com)
Date: Wed, 13 Nov 2002 23:05:22 +0100 (MET)
Subject: survreg (survival) reports erroneous results for left-censored data (PR#2287)
Message-ID: <200211132205.XAA24465@pubhealth.ku.dk>

Full_Name: Tim Cohn
Version: 1.6.1
OS: Macintosh OS X
Submission from: (NULL) (130.11.34.250)


The Mac version of survreg does not handle left-censored data correctly (at
least the results are not what I get doing it other ways, and they are not the
same as I get running R 1.6.1 in Windows 98se;  the Windows 98 results are
correct).  On the windows version of R 1.6.1. 

> survreg(Surv(c(0,1,-1),c(T,T,F),type='left')~1,dist='gaussian')
Call:
survreg(formula = Surv(c(0, 1, -1), c(T, T, F), type = "left") ~ 
    1, dist = "gaussian")

Coefficients:
(Intercept) 
 -0.2321569 

Scale= 1.161135 

Loglik(model)= -4.1   Loglik(intercept only)= -4.1
n= 3 


=================

The Macintosh OS X result for the same command is:

> survreg(Surv(c(0,1,-1),c(T,T,F),type='left')~1,dist='gaussian')
Call:
survreg(formula = Surv(c(0, 1, -1), c(T, T, F), type = "left") ~ 
    1, dist = "gaussian")

Coefficients:
(Intercept) 
 -0.7373613 

Scale= 1.366282 

Loglik(model)= -5.6   Loglik(intercept only)= -5.6
n= 3 


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survreg (survival) reports erroneous results for left-censored data (PR#2287)
tim@timcohn.com