|Re: Sorting on a 12C|
Message #5 Posted by Valentin Albillo on 29 Oct 2003, 10:53 a.m.,
in response to message #4 by Patrick
"Very nice, Katie. It only took... what? ... 21 years for someone to realize this?"
Not to belittle Katie's amazing sort in 21 steps, but seems to me you're implying that the possibility of using CFj in the HP-12C to achive indirect addressing of registers is a new discovery, unrealized for 21 years.
If that's what you mean, that's not the case. My "Serendipitous Solver" article, published in Datafile V21N2, (March/April 2002), 18 months ago, did include a program to evaluate and find roots of arbitrary polynomials in the HP-12C which already uses precisely this technique to indirectly access the storage registers where the coefficientes will be stored (see lines 05 and 12, as well as the description of the uses of CFj and CF0 in the article). I've seen no previous examples of this technique being used elsewhere, but it's quite possible that I wasn't the first to use it for practical purposes. In any case, it doesn't qualify as a new discovery.
All the same, kudos to Katie for its magnificent sort program. It would have made a superbly good challenge for all of us HP-12C lovers ("Given a set of n values stored in registers R0 to Rn, try and write a sorting routine in 21 bytes or less") :-) !!
Best regards from V.