I am puzzled by the warning message in the output below. It appears whether or not I fit the seasonal term (but the precise point of doing this was to fit what is effectively a second seasonal term). Is there some deep reason why AR parameters ("Warning message: some AR parameters were fixed: ...") should somehow intrude into the fitting of a model that has only MA terms?
> library(DAAG) > attach(bomsoi) > # The following is fine: > arima(avrain, order=c(0,0,4), seasonal=list(order=c(0,0,1), period=12), + fixed=c(NA,0,0,NA,NA,NA)) ..... > # The following generates a warning message > arima(avrain, order=c(0,0,4), seasonal=list(order=c(0,0,1), period=12), + fixed=c(0,0,0,NA,NA,NA)) Call: arima(x = avrain, order = c(0, 0, 4), seasonal = list(order = c(0, 0, 1), period = 12), fixed = c(0, 0, 0, NA, NA, NA)) Coefficients: ma1 ma2 ma3 ma4 sma1 intercept 0 0 0 0.0357 -0.1061 456.6675 s.e. 0 0 0 0.1015 0.0886 7.6997 sigma^2 estimated as 6849: log likelihood = -595.23, aic = 1198.46 Warning message: some AR parameters were fixed: setting transform.pars = FALSE in: arima(avrain, order = c(0, 0, 4), seasonal = list(order = c(0, John Maindonald email: [EMAIL PROTECTED] phone : +61 2 (6125)3473 fax : +61 2(6125)5549 Centre for Bioinformation Science, Room 1194, John Dedman Mathematical Sciences Building (Building 27) Australian National University, Canberra ACT 0200. ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html