Re: [R] Testing predictive power of ARIMA model

2008-12-15 Thread Gerard M. Keogh
Sorry, but this gives me the shivers! Are all your time series linear? For each model you should check the residuals and their squares to see if they are uncorrelated (Box-ljung Chi-sq). Another useful check is to test for a trend in the coefficient of variation of the residuals. If the series is

Re: [R] Testing predictive power of ARIMA model

2008-12-13 Thread Gad Abraham
Evan DeCorte wrote: Thanks for the great feedback. Conceptually I understand how you would go about testing out of sample performance. It seems like accuracy() would be the best way to test out of forecast performance and will help to automate the construction of statistics I would have calculated

Re: [R] Testing predictive power of ARIMA model

2008-12-13 Thread Evan DeCorte
Thanks for the great feedback. Conceptually I understand how you would go about testing out of sample performance. It seems like accuracy() would be the best way to test out of forecast performance and will help to automate the construction of statistics I would have calculated on my own. Howe

Re: [R] Testing predictive power of ARIMA model

2008-12-13 Thread Stefan Grosse
> for(i in 1:length(data)) > { > point_data = unlist(data[i], use.names = FALSE) > x = auto.arima(point_data , max.p = 10, max.q = 10, max.P = 0, max.Q = > 0, approximation = TRUE) > > } > > However, I would like to find a way to test the out of sample predictive > power of these mod

Re: [R] Testing predictive power of ARIMA model

2008-12-13 Thread Gad Abraham
Evan DeCorte wrote: I am trying to make estimates of the predictive power of ARIMA models estimated by the auto.arima() function. I am looping through a large number of time seiries and fitting ARIMA models with the following code. data1 <- read.csv(file = "case.csv", header = T) data <- data

[R] Testing predictive power of ARIMA model

2008-12-12 Thread Evan DeCorte
I am trying to make estimates of the predictive power of ARIMA models estimated by the auto.arima() function. I am looping through a large number of time seiries and fitting ARIMA models with the following code. data1 <- read.csv(file = "case.csv", header = T) data <- data1 output = c(1:leng