[Gretl-users] Testing the current CVS version

[Riccardo Jack Lucchetti]

On Tue, July 11, 2006 19:01, Sven Schreiber wrote:

> 3) In preferences/general, the choice between cholesky and QR could
> maybe use a short comment what this is about (I guess it must relate to
> how to solve (X'X)*beta = X'y ?)

You can find a good discussion of the QR algorithm in Davidson & MacKinnon
(1993): basically, Cholesky is cheaper numerically, whereas QR is more stable.
You're unlikely to see a difference unless you have regressors that are nearly
collinear.

> 4) Just a thought: maybe use 2sls instead of tsls, in analogy to 3sls,
> and both "two" and "three" start with t.

I agree. The only drawback is, if we allow a command to start with a number,
that could make the parsing code more complex (Allin?)

> 5) I like the new menu structure; however, iirc there used to be one
> menu less. Now the session menu is quite short, maybe make that a
> submenu of file? (I haven't thought this through, but staying at 7 menus
> would be better imho.)

I feel the same. Only, I'd put "Session" under "Utilities", which has less
entries (and seems more pertinent to me).

> 7) Whether or not variables are (set to) discrete should be displayed in
> the main window (by means of a little symbol, or a letter). And for
> discrete variables it would be nice to replace the histogram by a bar
> diagram where the bars are visually separated.

I agree on both things. For the graph, it's not easy to produce horizontal
bars with gnuplot. However, have a look at the attached screenshot.
It is produced by

open greene22_2
discrete Z6
freq Z6

after applying this simple patch:

Index: lib/src/graphing.c
===================================================================
RCS file: /cvsroot/gretl/gretl/lib/src/graphing.c,v
retrieving revision 1.280
diff -u -r1.280 graphing.c
--- lib/src/graphing.c  10 Jul 2006 02:49:47 -0000      1.280
+++ lib/src/graphing.c  11 Jul 2006 20:30:51 -0000
@@ -2050,6 +2050,10 @@
        return 1;
     }

+    if (freq->discrete) {
+       fprintf(fp, "set boxwidth 0.75\n");
+    }
+
     /* plot instructions */
     if (use_boxes) {
        if (gnuplot_has_style_fill()) {


Do you people like it? Allin, do you?



Riccardo "Jack" Lucchetti
Dipartimento di Economia
Facoltà di Economia "G. Fuà"
Ancona
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