Re: [R] negative AIC and BIC values in gls

2012-08-23 Thread Ingmar Visser
It's fine. Just interpret them as you would any other (lower is better). And it is the printed logLik that is out of step here. log-likelihoods _should_ be negative. That is not quite the case; in models with small variances log-likelihoods can easily become positive, consider eg:

Re: [R] negative AIC and BIC values in gls

2012-08-23 Thread Bert Gunter
O course! And for the same reason, my stupid comment should be ignored. -- Bert On Thu, Aug 23, 2012 at 12:02 AM, Ingmar Visser i.vis...@uva.nl wrote: It's fine. Just interpret them as you would any other (lower is better). And it is the printed logLik that is out of step here.

Re: [R] negative AIC and BIC values in gls

2012-08-23 Thread David Winsemius
On Aug 23, 2012, at 12:02 AM, Ingmar Visser wrote: It's fine. Just interpret them as you would any other (lower is better). And it is the printed logLik that is out of step here. log- likelihoods _should_ be negative. That is not quite the case; in models with small variances log-

[R] negative AIC and BIC values in gls

2012-08-22 Thread Gary Dong
Dear R users, I obtained negative AIC and BIC and positive Loglik values in a gls model. Is this normal? how should I interpret them? Thanks! AIC BIC logLik -659.978 -587.5541 345.989 Best Gary [[alternative HTML version deleted]]

Re: [R] negative AIC and BIC values in gls

2012-08-22 Thread Jeremy Miles
It's fine. Just interpret them as you would any other (lower is better). On 22 August 2012 16:43, Gary Dong pdxgary...@gmail.com wrote: Dear R users, I obtained negative AIC and BIC and positive Loglik values in a gls model. Is this normal? how should I interpret them? Thanks! AIC

Re: [R] negative AIC and BIC values in gls

2012-08-22 Thread David Winsemius
On Aug 22, 2012, at 5:17 PM, Jeremy Miles wrote: It's fine. Just interpret them as you would any other (lower is better). And it is the printed logLik that is out of step here. log-likelihoods _should_ be negative. -- David. On 22 August 2012 16:43, Gary Dong pdxgary...@gmail.com

Re: [R] negative AIC and BIC values in gls

2012-08-22 Thread Bert Gunter
Inline. On Wed, Aug 22, 2012 at 5:17 PM, Jeremy Miles jeremy.mi...@gmail.com wrote: It's fine. Just interpret them as you would any other (lower is better). I don't think so. I believe all 3 values are the negative of what they should be. AIC is defined as -2*log(L) + k*{degrees of freedom