On 10.09.2011 01:54, Stephen Sefick wrote:
Those are not "very" different. I would suspect they are within computer rounding error. Only numbers of log2 can be represented exactly, could that be it? Did you compiled the two versions differently, or could something have changed between 2.11.1 to 2.12.2 - both of which are old versions of R? If you provide a reproducible example I will gladly run it to compare your results with 2.13.1. Maybe somebody else will have a more helpful response.
No, you are so right: We do not no OS, architecture, 32 vs 64-bit, BLAS in use, compiler differences etc. on that machine, and minor numerical differences can be caused by anything.
Uwe Ligges
FWIW, Stephen Sefick On 09/09/2011 04:43 PM, Luis Felipe Parra wrote:Hello , I have estimated the following model, a sarima: p=9 d=1 q=2 P=0 D=1 Q=1 S=12 In R 2.12.2 Call: arima(x = xdata, order = c(p, d, q), seasonal = list(order = c(P, D, Q), period = S), optim.control = list(reltol = tol)) Coefficients: ar1 ar2 ar3 ar4 ar5 ar6 ar7 ar8 ar9 0.3152 0.8762 -0.4413 0.0152 0.1500 0.0001 -0.0413 -0.1811 0.0646 s.e. 0.0865 0.0885 0.1141 0.1181 0.1196 0.1220 0.1120 0.0908 0.0865 ma1 ma2 sma1 -0.0221 -0.9779 -0.7635 s.e. 0.0539 0.0534 0.0834 sigma^2 estimated as 1.965e+17: log likelihood = -3316.07, aic = 6658.13 and in In R 2.11.1 Call: arima(x = xdata, order = c(p, d, q), seasonal = list(order = c(P, D, Q), period = S), optim.control = list(reltol = tol)) Coefficients: ar1 ar2 ar3 ar4 ar5 ar6 ar7 ar8 ar9 0.3152 0.8761 -0.4413 0.0153 0.1500 0.000 -0.0413 -0.1810 0.0646 s.e. 0.0865 0.0885 0.1141 0.1181 0.1196 0.122 0.1120 0.0908 0.0865 ma1 ma2 sma1 -0.0221 -0.9779 -0.7635 s.e. 0.0539 0.0534 0.0834 sigma^2 estimated as 1.965e+17: log likelihood = -3316.07, aic = 6658.13 and as you can see in the results some coefficients (for example ar2 and ar8) are different in the different R versions. does anybody know what might be going on. Was there any change in the arima function between the two versions? Thank you Felipe Parra ______________________________________________ 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.[[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.
