[R] loglik and arima()

2009-02-10 Thread Stephen Collins
All - 

I am evaluating an arima(2,1,3) and arima(3,1,3) and notice the 
log-likelihood of the restricted model is higher than the log-likelihood 
of the unrestricted. 

Since these are nested models, I thought the unrestricted model would have 
a log-likelihood at least as large as that of the restricted model.  Am I 
interpreting the loglik output incorrectly?

Regards,

   
Stephen Collins, MPP | Analyst
Health  Benefits | Aon Consulting
200 East Randolph, Suite 900, Chicago, IL
Tel: 312-381-2578 | Fax: 312-381-0136
Email: stephen_coll...@aon.com
 
Aon Consulting selected by the readers of Business Insurance as the “Best 
Employee Benefit Consulting Firm” in 2006, 2007, and 2008
 
NOTE: The information contained in this transmission, including any 
attachment(s) is only for the use of the intended individual(s) or entity, 
and may contain information that is privileged and confidential. If the 
reader of this message is not an intended recipient, you are hereby 
notified that any dissemination, distribution, disclosure, or copying of 
this information is unauthorized and strictly prohibited. If you have 
received this communication in error, please contact the sender 
immediately by reply email and destroy all copies of the original message.
 

[[alternative HTML version deleted]]

__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


Re: [R] loglik and arima()

2009-02-10 Thread markleeds
 hi: maybe it's minimizing the negative of the likeihood rather than 
maximizing the likelihood ?
other than that, i don't see that being possible because of what you 
said. see what

happens if you estimate an arima(1,1,3) ?





On Tue, Feb 10, 2009 at 12:51 PM, Stephen Collins wrote:


All -
I am evaluating an arima(2,1,3) and arima(3,1,3) and notice the 
log-likelihood of the restricted model is higher than the 
log-likelihood of the unrestricted.
Since these are nested models, I thought the unrestricted model would 
have a log-likelihood at least as large as that of the restricted 
model.  Am I interpreting the loglik output incorrectly?


Regards,

   Stephen Collins, MPP | Analyst
Health  Benefits | Aon Consulting
200 East Randolph, Suite 900, Chicago, IL
Tel: 312-381-2578 | Fax: 312-381-0136
Email: stephen_coll...@aon.com
 Aon Consulting selected by the readers of Business Insurance as the 
���Best Employee Benefit Consulting Firm��� in 2006, 2007, and 2008
 NOTE: The information contained in this transmission, including any 
attachment(s) is only for the use of the intended individual(s) or 
entity, and may contain information that is privileged and 
confidential. If the reader of this message is not an intended 
recipient, you are hereby notified that any dissemination, 
distribution, disclosure, or copying of this information is 
unauthorized and strictly prohibited. If you have received this 
communication in error, please contact the sender immediately by reply 
email and destroy all copies of the original message.


[[alternative HTML version deleted]]



 --

__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide 
http://www.R-project.org/posting-guide.html

and provide commented, minimal, self-contained, reproducible code.


__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.