Re: Re: [Gretl-devel] Bugs, missing features and a suggestion
On Wed, 26 Sep 2007, andreas.rosenblad(a)ltv.se wrote:
Well, currently I have to do as follows:
a = rows(A)
smpl 1 a
series Anew = A
series Bnew = B
xtab Anew Bnew
delete Anew bnew
smpl --full
Thus, I have to use 7 commands. Instead I would like to use just one
command:
xtab A B
It would be much easier and efficient, having to write less code. So I
would really appreciate it.
I see your point; I may even concede that adding this feature to the xtab
command could be worth the trouble. However, the reason why user-level
function are present in gretl is exactly to handle cases like yours. I
don't see why it should be a problem to wrap your sequence of commands
into a function.
For a matrix C = {3,2;2,3} gretl currently give the following
output:
? C
C (2 x 2)
3 2
2 3
What I am asking for is following output
? xtab C
[ 1][ 2] TOT.
[ 1] 3 2 5
[ 2] 2 3 5
TOTAL 5 5 10
I need this function mainly for producing nice outputs with column and row
headings, and I thought this would be the easiest way to implement it.
Let's separate the issues: in theory, you can get the numbers easily by
something like
D = ( C ~ sumr(C) ) | ( sumc(C) ~ sumc(sumr(C)) )
but this seems not to work at present; it's a bug, and I thank you for
unearthing this. However, the following workaround does work:
D = C ~ sumr(C)
e = sumc(C) ~ sumc(sumr(C))
D = D | e
As for the labels, I think there's no easy way out: the information
contained in the matrix tells you nothing on the labels that you want
printed, so your next point may be interesting.
A better solution, that better suits my needs, but maybe is harder
to
implement, is to create a new "printtable" command that attaches column and
row names to a matrix (something like the dimnames argument in the matrix
command in R) as well as row and column headings.
Ideally, a command "printtable" would produce something like:
A = {3, 2, 5; 2, 3, 5; 5, 5, 10}
printtable A rownames={"row 1", "row2", "Total"}
columnnames={"col 1", "col
2", "Total"} \
columnheading="Variable 1" rowheading="Variable 2"
And then with this input give the following output:
Variable 1
col 1 col 2 Total
row 1 3 2 5
Variable 2 row 2 2 3 5
Total 5 5 10
Would this be possible to implement in gretl?
As things stand now, this would be a bit hard since gretl has no concept
of an array that you can fill in with strings (to put it simply). If this
extension was implemented (not a priority IMO) it would not be difficult
to write a user-level function like
printtable(matrix A, strarray rownames, strarray colnames, string chead, \
string rhead)
by using the already amazingly flexible printf command.
>> 3. After calculating a cross classification table from View
> Cross
>> Tabulation in the GUI, one gets the possibility to save the output
table as
>> a matrix. This feature should be available also from the command line
>> interface.
>
> This is exactly what the mxtab function is for. Am I missing something?
I'm sorry, I couldn't find anytning about that function in the Gretl
Command Reference, the Gretl User's Guide or the help files.
Oof, you're right, sorry. It's not in the manual. I'll update it as soon
as I can.
Riccardo (Jack) Lucchetti
Dipartimento di Economia
Università Politecnica delle Marche
r.lucchetti(a)univpm.it
http://www.econ.univpm.it/lucchetti