Re: [R] Maximum likelihood estimation in R

[Spencer Graves]

     I got the same error message in R 1.8.1 and S-Plus 6.1.  Then I 
read the error message:  "'start' must be a named list".  Then I read 
help("fitdistr") and learned that "fitdistr" required 3 arguments, the 
third of which was "start: A named list giving the parameters to be 
optimized with initial values.  This can be omitted for some of the 
named distributions (see Details)."  The normal distribution was NOT one 
of the named distributions.  When I supplied a named list for "start", 
it worked: 

> fitdistr(x, "normal", list(mean=0, sd=1))
     mean          sd   
 2.97093013   0.88852969
(0.08885297) (0.06281083)

     hope this helps.  spencer graves

Rau, Roland wrote:

Hi,

 

-----Original Message-----
From:   [EMAIL PROTECTED] [SMTP:[EMAIL PROTECTED]
Sent:   Sunday, February 15, 2004 10:24 PM
To:     [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject:        Re: [R] Maximum likelihood estimation in R
Hello,

Use

   

x=rnorm(100, mean=3, sd=1)
library(MASS)
fitdistr(x, "normal")
     

     mean          sd    
 2.93666631   0.99673982 
(0.09967398) (0.07048015)

   

        For me, this example does not work. As it looks like copy+paste, I
guess this something platform dependent? At least I have to specify some
starting values as shown below. But maybe I did something wrong?
        Best,
        Roland
        (I am using at the moment R 1.8.1 on WinNT)
	> x=rnorm(100, mean=3, sd=1)
	> library(MASS)
	> fitdistr(x, "normal")
	Error in fitdistr(x, "normal") : 'start' must be a named list
	> fitdistr(x, "normal", start=list(mean=1, sd=0.4))
	      mean          sd    
	  3.03167815   1.06637851 
	 (0.10663786) (0.07539617)
	> 

+++++
This mail has been sent through the MPI for Demographic Research.  Should you receive 
a mail that is apparently from a MPI user without this text displayed, then the 
address has most likely been faked.   If you are uncertain about the validity of this 
message, please check the mail header or ask your system administrator for assistance.
______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
 

______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html