mm wrote:

....

Btw, is inv_tdist in public domain?
....


The first line of the VBA code is a copyright notice, so by definition,
it is not public domain.

However, if Ian Smith had not intended for individuals to use his code,
then I doubt that he would have published the source code in a public
place. If you are wanting to use it commercially, I would recommend
e-mailing him. His address ) is clearly displayed
on his web page
http://members.aol.com/iandjmsmith/
and I have found him to respond readily to communications regarding his
numerical analysis efforts. Ian?

Jerry