Thank u Jack for this nice solution!
Leon
Am 25.02.2013 um 01:20 schrieb "Riccardo (Jack) Lucchetti"
<r.lucchetti(a)univpm.it>:
> On Sun, 24 Feb 2013, Pindar wrote:
>
>> Hi,
>>
>> I'd like to point out, that a 'good' 'aggregate by' function would do such a
>> job as described below.
>> Unfortunately I'm stuck with more then bivariate interaction but I'm sure
>> GRETL can do this,
>> this question is how!
>
> The script below should do what I think you need; the trick is creating a
> series which contains, in coded form, all the possible combinations of values
> of the variables contained in a list. This is what the function "pack" does;
> note that "pack" also creates a matrix which is used in the "unpack" function
> later.
>
> See if this helps:
>
> <hansl>
> set echo off
> set messages off
>
> function series pack(list X, matrix *pwrof2)
> /*
> a check should be necessary that all series in X
> are discrete; for the moment, let's just skip it
> */
>
> series ret = 0
> pwrtot = 1
> k = nelem(X)
> # first build the nvalues vector
> pwrof2 = {}
> n = 1
> k = 1
> loop foreach i X --quiet
> ret += k*X.$i
> n = 2^ceil(log2(1+max(X.$i)))
> k *= n
> pwrof2 |= n
> end loop
>
> return ret
> end function
>
> function matrix unpack(scalar x, matrix pwr)
>
> k = rows(pwr)
> matrix ret = zeros(k,1)
>
> loop i=1..k --quiet
> h = pwr[i]
> a = x % h
> ret[i] = a
> x = (x-a)/h
> end loop
>
> return ret
> end function
>
> # --- END FUNCTIONS -----------------------------------------
>
> open pizza4.gdt
> series ages = age<=20 ? 0 : (age>20 && age <=40) ? 1 : 2
>
> list A = female hs ages
> matrix codes = {}
> u = pack(A, &codes)
>
> n_u = values(u)
> loop i = 1..rows(n_u) --quiet
> k = n_u[i]
> smpl u==k --restrict --replace
> c = unpack(k, codes)
> l = 1
> loop foreach j A --quiet
> printf "%10s = %d", "$j", c[l]
> l++
> end loop
>
> printf "\ncases = %d, mean(pizza) = %g, mean(income) = %g\n\n", \
> $nobs, mean(pizza), mean(income)
> end loop
>
> smpl full
> </hansl>
>
>
>
>>
>> It's even more complex since the R function is not that good either, cos
>> e.g. for MAVOVA one needs the variance-covariance-structure of
>> the 'interaction series'. That's why in GRETL lists should be processed
>> which makes the stuff not easier.
>>
>> I worked around with the new '^' operator and have some promising results,
>> but a build-in function would be the best.
>>
>> Cheers
>> Leon
>>
>> <hansl>
>> open pizza4.gdt
>> series ages = age<=20 ? 0 : (age>20 && age <=40) ? 1 : 2
>> set echo off
>> foreign language=R --send-data --quiet
>> library(plyr)
>> ddply(gretldata[,c(1,2,4,6,8)], ~ female + college + ages,
>> numcolwise(mean))
>> end foreign
>> <hansl>
>>
>> While the bivariate case in rather easy as in
>>
>> <hansl>
>> open pizza4.gdt
>> set echo off
>> series ages = age<=20 ? 0 : (age>20 && age <=40) ? 1 : 2
>>
>> list G1 = 2 4
>> list G2 = 2 8
>> list G3 = 4 8
>> list G = G1 || G2
>>
>> scalar times = 2 # should also be
>> possible to be set to nelem(G)
>>
>> #set up of all combination list
>> loop for i=2..times -q
>> string listName = "inter$i"
>> list @listName = null
>> endloop
>>
>> list part1 = null
>> list part2 = G
>>
>> # bivariate interaction
>> loop foreach i G-q
>> part1 = G.$i
>> part2 -= G.$i
>> inter2 += part2^part1
>> part2 += G.$i
>> endloop
>> <hansl>
>>
>>
>>
>> Am 20.02.2013 17:45, schrieb Riccardo (Jack) Lucchetti:
>>> On Wed, 20 Feb 2013, Allin Cottrell wrote:
>>>> On Wed, 20 Feb 2013, Riccardo (Jack) Lucchetti wrote:
>>>>> Very nice. The next step, logically, would be to support user-written
>>>>> functions too. However, this would mean to complicate the code by a
>>>>> factor (I reckon) of 1 to 5 or so.
>>>> I was afraid the factor might be at the top end of that range, but I
>>>> experimented and it's more like 0.25. So user-functions are now supported.
>>>> The function must take a single series argument and return a scalar.
>>>> Example:
>>>> <hansl>
>>>> function scalar my_aggregator (series x)
>>>> return sum(x^3)
>>>> end function
>>>> open credscore.gdt
>>>> matrix m = aggregate(Income, Acc, my_aggregator)
>>>> print m
>>>> </hansl>
>>> Now, I don't want to be guilty of personality cult, but at the risk of
>>> sounding like an old Stalinist apparatchik I have to say I am left in awe
>>> by the skills of our beloved leader.
>>> Studying the cvs diff has been for several years my primary method for
>>> learning C, but this case stands out as a true gem.
>>> Thank you.
>>> -------------------------------------------------------
>>> Riccardo (Jack) Lucchetti
>>> Dipartimento di Scienze Economiche e Sociali (DiSES)
>>>
>>> Università Politecnica delle Marche
>>> (formerly known as Università di Ancona)
>>>
>>> r.lucchetti(a)univpm.it
>>> http://www2.econ.univpm.it/servizi/hpp/lucchetti
>>> -------------------------------------------------------
>>> _______________________________________________
>>> Gretl-users mailing list
>>> Gretl-users(a)lists.wfu.edu
>>> http://lists.wfu.edu/mailman/listinfo/gretl-users
>
> -------------------------------------------------------
> Riccardo (Jack) Lucchetti
> Dipartimento di Scienze Economiche e Sociali (DiSES)
>
> Università Politecnica delle Marche
> (formerly known as Università di Ancona)
>
> r.lucchetti(a)univpm.it
> http://www2.econ.univpm.it/servizi/hpp/lucchetti
> -------------------------------------------------------
