On Tue, 7 Jun 2005, Adrien BETON wrote:
Hello
I am a student working on ozone datas and i would like to use an arima
data to correlate ozone datas and gas emissions in order to predict
future ozone levels basing on other gas emissions.
Gretl should allow me to do this but I am not very used to statistics
and modelling.
Gretl should handle rather comfortably basic stuff. What you probably need
is some kind of armax model, as far as I can tell.
Therefore I have two questions :
How can I set my datas (setobs) knowing that I have values of ozone each
30' during 6 days (48*6=288 values), gretl only recognize yearly datas ?
No, but there is no support so far for infra-hour data. Your best bet is
to set yout dataset to Time Series/Other.
What model do you suggest me to use in order to build a model
linking
ozone to gas in order to forecast ozone levels based on the gas ?
It really depends on the data. In your case, it is important to se how
strong the 24-hour cycle is.
If I can t do this with gretl, what other softwares do you suggest me
to
try ?
In the realm of free software, you might probably want to have a go with
R (
www.cran.org); R, however, is considerably more complex to use than
gretl.
I hope that someone could help me :-)
I hope this helps.
Riccardo `Jack' Lucchetti
Dipartimento di Economia
Università di Ancona
jack(a)dea.unian.it
http://www.econ.unian.it/lucchetti