[R] SSweibull

Lüdde Mirko mirko.luedde at cellcontrol.de
Tue Jun 26 20:31:26 CEST 2001

Dear all, 

I'd like to use the `SSweibull' function for survival analysis.  In
order to become acquainted with the function, I said `help(SSweibull)'
and went through the example. What puzzles me is 

1. What should I make of the assertion `Initial values are in fact the
   converged values'?

2. When doing a `SSweibull(Chick.6$Time, Asym, Drop, lrc, pwr)' 
   I can see no indication of convergence of the values whatsoever.
   On the other hand, plotting the object yields a nice Weibull curve.

3. Wouldn't it be nice to have some formulas in the help section 
   precisely explaining the meaning of the parameters? There
   are several parametrizations of the Weibull distribution. 

Cheers, Mirko. 
Dr. M. Luedde <Mirko.Luedde at CellControl.De>
CellControl Biomedical Laboratories AG
Am Klopferspitz 19, 82152 Martinsried
+49-89-895275-0 +49-179-5252064 
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