Re: [Gretl-users] using gretl for AR(1) modeling of daily time series
On Wed, 13 Jul 2005, Deepak Muricken wrote:
I am trying to use gretl for modeling daily data as opposed to
yearly data.
That should be possible.
I feel that this is possible as one of the sample data (file data
10-2), hourly load and temperature data seem to be compatible for
time series analysis. The data is an hourly information.
That's a bit different: hourly data is "intra-day" rather than
daily.
What I have with me is daily observation which I wish to use in
the format given below.
obs (meaning)
8:01 1 st of August
8:02
.......
8::30 30 th of August
The problem here is that, in gretl, the observation syntax "X:Y" --
where "X" indicates a "major" period and "Y" a
"minor" period --
works only when the frequency or periodicity is constant. For
example, it works if X indexes a year and Y a quarter; or X indexes
a year and Y a month; or X indexes a day and Y an hour.
For months and days, the obvious problem is that not all months have
the same number of days, so we do not have a constant periodicity.
In this case you can index the observations by calendar date. If
you import the data into gretl, you can then go to the Sample menu
and select "Dataset structure": this presents you with a series of
dialog boxes whereby you can define the data as daily, with a
specific starting date.
Allin Cottrell.