Re: [R] AICc vs AIC for model selection

2006-07-17 Thread Sachin J
Hi Spencer, I did go through the previous postings in the mailing list. But couldn't find satisfactory answer to my question. I am dealing with univariate time series. I suspect that my data may contain some trend and seasonal components. Hence, rather than just fitting just AR(1) model,

Re: [R] AICc vs AIC for model selection

2006-07-17 Thread Spencer Graves
I understand that you have only 26 observations. Model identification always requires more observations than estimating a model you already think you know. If it were my problem, I think I'd first plot the data over time and make a normal probability plot of the data. Then I'd

Re: [R] AICc vs AIC for model selection

2006-07-15 Thread Spencer Graves
Regarding AIC.c, have you tried RSiteSearch(AICc) and RSiteSearch(AIC.c)? This produced several comments that looked to me like they might help answer your question. Beyond that, I've never heard of the forecast package, and I got zero hits for RSiteSearch(best.arima), so I can't

Re: [R] AICc vs AIC for model selection

2006-07-15 Thread Kjetil Brinchmann Halvorsen
Spencer Graves wrote: Regarding AIC.c, have you tried RSiteSearch(AICc) and RSiteSearch(AIC.c)? This produced several comments that looked to me like they might help answer your question. Beyond that, I've never heard of the forecast package, and I got zero hits for

Re: [R] AICc vs AIC for model selection

2006-07-15 Thread Spencer Graves
Hi, Kjetil: Thanks. Spencer Graves Kjetil Brinchmann Halvorsen wrote: Spencer Graves wrote: Regarding AIC.c, have you tried RSiteSearch(AICc) and RSiteSearch(AIC.c)? This produced several comments that looked to me like they might help answer your question. Beyond that, I've

[R] AICc vs AIC for model selection

2006-07-13 Thread Sachin J
Hi, I am using 'best.arima' function from forecast package to obtain point forecast for a time series data set. The documentation says it utilizes AIC value to select best ARIMA model. But in my case the sample size very small - 26 observations (demand data). Is it the right to use AIC

[R] AICc vs AIC for model selection

2006-07-12 Thread Sachin J
Hi, I am using 'best.arima' function from forecast package to obtain point forecast for a time series data set. The documentation says it utilizes AIC value to select best ARIMA model. But in my case the sample size very small - 26 observations (demand data). Is it the right to use AIC