In my v2.2 program I included an experimental FHT version.

The FHT stands for Fast Hartley Transform.  It's very similar to the
FFT (Fast Fourier Transform.)

When  I  was  did   that,   however,   I   forgot  about  the  legal
complications.  (No lawyers have shown up at my  door,  or  anything
like that.)  I was just experiementing and just simply forgot  about
it when it came time to 'ship' v2.2.


It appeares that Bracewell has somehow managed to  claim  patent  on
the  entire  FHT concept.  Not just a particular implementation, but
the  entire  concept  of  doing  a  'Fast'  version  of  the Hartley
Transform.  That's quite a stretch considering the Hartley transform
was developed 50 years ago, and the tehcniques to split that type of
transform (ie:  the Fourier Transform) into the 'Fast' variety  were
developed  30  years ago (Cooley, etc.) and possibly even far before
that (Gauss).

For the record, I developed my FHT code directly  from  a  recursive
Fast  Fourier  program and the Hartley mathematical formula.  It was
almost a straight, simple  conversion  to  the FHT program simply by
replacing the complex function with Harltey's 'cas' function.

However, as I am in absolutely  no  financial  position  to  legally
challenge Bracewell (note no 'Mr.' in front of his name as a sign of
respect....!   I  have  a strong opinion of people who file software
/ mathematical patents) or his patent, that code may or may not fall
under  his  legal patents.  (I think somebody needs to have a rather
forceful conversation with him  and  teach  him that mathematics and
patents don't go together!  Perhaps fill your mouth with cotten  and
make  him  "an  offer  he  can't refuse"<g> (For you foreign people,
that's a reference to the movie "Godfather", with Brando).)


I really, really, considered removing  it.   And  I did for a while.
But one beta tester kept strongly encouraging me to put it back  in,
so....   Be  sure  and  read  the legalities in the fftstuff\hartley
directory.


