Manipulating a database
by Leandro Zipitria
Hello Gretl Community,
I have a database with daily prices which is in a rather unusual format and
I want to know if it is possibly to create a panel data with it using Gretl
scripts. The database is extracted from a dbf archive, and its has 6
variables:
- The (number of) supermarket from which the price is reported
- The (number of) the product which price is being reported
- The year of the price
- The month of the price
- The price reported itself
- The first day of the month the price is reported
- The last day of the month the price is reported
I have nearly one million rows with data, but in order to do some
regressions -and use it as a panel- I will need to transform it in a
suitable way.
I suppose that the best way that Gretl can handle it is to create a specific
column for each product, and then stack all the supermarkets on a daily
basis. In this way, I will have each column representing a product, the
first 700 rows being a price for each product for supermarket 1, the next
700 rows being a price for each product for supermarket 2, etc.
But in order to do it, I will need first to create the daily prices series,
which is now "compacted" in the datafile. I am attaching a random 10
elements from the database in order to get a better picture of the
situation. In the first sheet I submit the actual data format, on the second
one which I think should be the (best?) result.
I will first ask if this kind of transformation is possible in Gretl. I am
aware that running some scripts on other programs could do the trick, but I
think that it could be possible in Gretl to do it. But I am also think that
it could be rather complex to do it, and I am a new one on this issues.
Thank in advance.
Best regards,
Leandro Zipitría
14 years, 8 months
periodogram
by Javier García
Am 01.07.2010 02:16, schrieb Allin Cottrell:
>
> On Wed, 30 Jun 2010, [iso-8859-1] Javier Garc?a wrote:
>
>> Yes, with the spectrum there is no problem, the problem appears when
>> you select the periodogram (/Variable/Spectrum/ sample periodogram)!
>
> Ah, OK, I see what you mean. This is noew fixed in CVS.
>
Hold on a sec -- that's what the other submenu entry in /Variable/Spectrum
below "periodogram" is and has always been for, no?
The periodogram itself of course doesn't have any smoothing, so no
bandwidth. Though I guess one could argue to substitute the two-item submenu
under /Variable/Spectrum with a single dialog offering the choice instead.
I dont think so because, while in the periodogram you select the bandwidth
of the semiparametric estimators, in the spectrum you choose the bandwidth
to smooth the periodogram. They are different concepts.
Cheers
Javi
14 years, 8 months
Periodogram
by Javier García
Hi, Allin;
Yes, with the spectrum there is no problem, the problem appears when you
select the periodogram (/Variable/Spectrum/ sample periodogram)!
Cheers
Javi
14 years, 8 months
Wilcoxon Signed-Rank Test
by yinung＠Gmail
Dear all
I run the Wilcoxon Signed-Rank Test with x and y in the attached gdt
file but the gretl crashed (under windows XP).
I am not sure If the problem is resulted from the data in y?
Thanks
Yi-Nung
14 years, 8 months
