Using Tk table widget to display matrix

Has anyone written a matrix editor or data.entry() replacement using the Tk
table widget?  I've been playing around with the examples at

http://bioinf.wehi.edu.au/~wettenhall/RTclTkExamples/tktable.html

and making some progress, but I'd rather not spend much time on this if
someone else has already done it.

Jeff