newRPL  build 1255 released! [updated to 1299]

08152019, 10:49 PM
Post: #562




RE: newRPL  build 1255 released! [updated to 1282]
(08022019 07:57 PM)The Shadow Wrote: Claudio, it might be worth looking at the PDQ algorithm as a replacement for the >Q algorithm currently in use. Not only will it fix the "overshooting" problem I mentioned a while back, but it has other desirable properties. (Naturally for use in >Q the tolerance would be taken from the system settings and one wouldn't bother calculating the error. But the fullblown PDQ might make a worthy command in its own right.) I did replace the >Q algorithm with PDQ (not published yet). Works nice but what should be the tolerance for >Q? I did the obvious: Use the 10^(prec) where prec is the current precision. However, the algorithm seems to have some glitches. Works great in some cases, bad in others for example: 12345678 13 / >Q results in '12345678/13' (no surprises there) 12345678 7 / >Q results in '1.763 667 051E31/9.999 993E24' (note: not all digits survived copy/paste from newRPL Desktop) Doing >NUM on this bizarre fraction, I get the original argument *exactly* with all 32 digits matching, so this fraction IS a correct result, just not what I thought I would get: '12345678/7' (ohhhhhh.... moment) I just figured it out while typing this! Thanks to the forum... If the argument has already 7 integer digits there's only 327=25 digits after the decimal point, so a tolerance of 10^32 is simply "locking to zero" 7 digits after the last known digit. So I'm adding 7 zeros after the number, and forcing the system to approximate *that* number. Clearly, I just need to determine how many "fractional" digits are in the actual argument and use that as tolerance 

« Next Oldest  Next Newest »

User(s) browsing this thread: 2 Guest(s)