[Rd] need gui matrix editor: does R Core team have advice on how?

[Paul Johnson]

Dear R-devel:

Would R core team consider endorsing a graphical toolkit and trying to
facilitate development of little GUI tools?

I need a gui matrix editor for users that want to be able to write
matrices that are later used to simulate data.  Instead of teaching
them to write a covariance matrix (for example, for mvtnorm), I want
to tell them run a function that pops up a table they can fill in.

The users need to be able to enter variable names in the matrix, so
something that would accept

a  0  0
0  b  0
c  d  e

would be great.  Something that would accept formulae like this would
be even more great.

a  0  0
0  b  a^2
c  d  e

I want this gui matrix editor to "just work" on Windows, Mac, Linux. I
don't mind building this on top of some widget set, but it is
important that the widget set be easily installable on the user end.

That's why I wish R core would offer us some guidance or advice.  I'm
not a programmer, but I can learn to program with a library, as long
as it is not a waste of time.

I've been searching R archives and here's what I found so far.

1. tcl/tk

Building on R tcltk2, for people that have the Tcl addon widget
TkTable installed, there are several packages.  in tcltk2 itself,
there is a function tk2edit, and there are others that try to
embellish.  I've tried several of these, they seem to be not-quite
done yet, one can't copy a rectangle, for example. But maybe I could
learn how to fix them up and make yet another tktable based editor.

Problem: requires user to have enough understanding to install the Tcl
widget TkTable.  And, for platforms like Windows, user has to install
tcl/tk itself.  On Linux and Mac, that is not as big of a hurdle, so
far as I can tell.  On Debian linux, I found that in a package
libtktable that works, but I have no idea how tough that would be on
other linux systems or Macintosh or Windows.

Another problem is that tcl/tk editions change rapidly, and on several
of our systems, we still don't have access to tcl/tk 8.5
(RedHat/Centos based clusters still running version 5 are like that).

2. Gtk

Building on Rgtk, I found the package RGtk2Extras.  This of course
requires a function gtk tool chain, which used to be a big problem on
the various platforms.  But the function dfedit appears to be almost
exactly what I'm looking for.  I can create a character matrix and put
in letters how I want, but I later face the problem of how to evaluate
the matrix.

Problem: even more than tcl/tk, GTK versions change and become
incompatible, especially across platforms.

What about QT or WX-Widgets.  I gather RkWard is built on KDE, and
hence Qt.  I don't find matrix editors using those languages, but I
don't know why not.

Maybe this is impossible for R core to advise us because you may
disagree on which widget library is best, but if there is some
consensus, I would be glad to know because I would do whatever you
recommend.

I'm pretty sure that, if you said, "use library X, version XYZ", then
the worldwide usage of R is sufficiently broad that people would step
forward and help make sure those libraries are packaged for all OS.  I
mean, if there were no tktable package for any linux for which I make
packages (RedHat, Fedora, Debian, Ubuntu), I would create the
packages.   But I'm not doing it now because I have no reason to
believe that is a good path from here on out.


-- 
Paul E. Johnson
Professor, Political Science
1541 Lilac Lane, Room 504
University of Kansas