[R-gui] regression diagram builder thingie? Maybe like Doodle in Winbugs?

[Paul Johnson]

I'd like to have an R program that allows users to design regression
equations by dragging variables around in a canvas, to interactively
build path diagrams that lead to regressions. The diagrams would
generate code that would run, and then results would somehow be linked
to the drawings, perhaps showing coefficients on the edges or such.

I'd like this thing to facilitate multilevel modeling if possible, but
I'd settle to just have a pallet of variable "nodes" that can be
pulled out of a box on the side and re-positioned in the canvas, with
arrows pointing in and out. If that could generate code to run glm,
I'd be happy.

Then I'd like to generalize this so that the nodes could represent
latent variables in a structural equation model.  Maybe I'd fiddle it
up to write code for fitting with lavaan's estimators.

Has anybody tried to do such a thing?  Anybody know where to start?

If you were doing this, which of the graphical programming
environments would you suggest?  I want this to work more-or-less well
on all platforms. I've Googled enough to know it is not easy to decide
which path to follow.  My first idea was to imitate the design of
programs that draw mind maps, but they are mostly based on Java, which
in my experience is hard to support for diverse platforms. Still, the
JGR project seems to do well with it, so I'm not absolutely opposed.

I've been looking at GTK2, QT4, WXwidgets and tcltk. Judging from what
I read in the email lists of various development projects, perhaps QT4
is the least troublesome multi-platform gui library, but it is not
entirely open/free.  QT, of course, is the underlying framework of the
KDE desktop.  My favorite editor, LyX, is written with QT, so I am
sure it works. The Gambit game theory project chose WX.  It appears to
me that tcltk is constantly on the brink of extinction, and yet new
versions pop out now and then.

In WinBUGS, there's a graphical model designer called Doodle that is
quite pleasing to me, but it seems there must be something wrong with
it because nobody boasts about it very much :(

pj
-- 
Paul E. Johnson
Professor, Political Science    Assoc. Director
1541 Lilac Lane, Room 504     Center for Research Methods
University of Kansas               University of Kansas
http://pj.freefaculty.org            http://quant.ku.edu