On Sun, 29 Jun 2014, Sven Schreiber wrote:
Am 29.06.2014 02:07, schrieb Allin Cottrell:
> On Sat, 28 Jun 2014, Sven Schreiber wrote:
>
>> the attached file is the result from compacting monthly series to quarterly.
>> When I try to compact further to annual then I don't get any options
>> (average, summing, etc.). But I do get the options when I try other files.
>>
>> Is it because gretl is particularly clever (remembering the prior compacting
>> method)? In which case I would find a corresponding message in the dialog
>> window useful. Or is it just a bug?
>
> Well, if you take a look inside your XML data file (use "less" or
> perhaps "zless" on Linux) you'll see that the series named US48Temp
> has the following recorded:
>
> <variable name="US48Temp"
> compact-method="COMPACT_AVG"
> />
>
> So it seems that gretl is remembering what you chose last time and
> is assuming it still applies. Maybe we should print a message, but
> can you think of a use case where you'd want to use one method when
> compacting from monthly to quarterly, and a different method when
> going from quarterly to annual?
>
Well I'm not sure if it's very relevant, but in principle I guess you
might want to have the last-quarter value, even though that was an
average over the months in that quarter (in the case of interest rates
for example). I see no reason for gretl to outsmart the user here.
But my main point was that the user (who doesn't look into xml) isn't
informed which method is used. It's not obvious that it's the same
person that did the prior conversion, or that the user remembers what he
did earlier, so I think the information would be important.
Looking back at this I notice that it's explained quite clearly in the
text brought up by the Help button in the data compaction dialog: it tells
you where to find the specified compaction method for a given series in
the GUI, and also states that if methods are already chosen for all series
you won't get the compaction method option buttons.
The case you gave is a bit special in that there's only one series in the
dataset. In that case, it seems reasonable to show the "methods" buttons,
with the one that's already specified shown as pre-selected. I've made
that change in CVS.
Allin