Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!olivea!mintaka!bloom-beacon!eru!kth.se!sunic!sics.se!fuug!news.funet.fi!tukki.jyu.fi!jadbalja!tt From: tt@jadbalja.jyu.fi (Tapani Tarvainen) Newsgroups: comp.sys.handhelds Subject: Re: Accuracy w/ ln and log Keywords: HP Message-ID: Date: 6 Jun 91 07:25:39 GMT References: <1991May30.120658.3590@panix.uucp> <3630@charon.cwi.nl> Sender: news@jyu.fi (News articles) Organization: University of Jyvaskyla Lines: 21 In-Reply-To: Marek Vokac's message of Wed, 5 Jun 1991 10: 36:30 GMT Originator: tt@jadbalja.jyu.fi Nntp-Posting-Host: jadbalja.jyu.fi In article Marek Vokac writes: >I _think_ chained calculations on the HP are precise to 12 digits You are definitely correct -- as far as normal user-level language is concerned. In "system RPL" I expect it would be easy to use extended precision all the time and round only when it suits you. It might also be possibly to use the Extended type in user RPL, by replacing normal function calls with calls to the internal, non-rounding routines (via SYSEVAL maybe, else with short machine code). >Morale: Yes, the HP48 is precise; that precision has its limits (as >with all finite machines), and the logarithm functions are not >_always_ correct - of course! But they could be always _correctly rounded_ (even though I don't think they are). The basic arithmetic funtions have been that way since the HP41, I believe (but weren't in the 67/97). (My memory is a bit vague here, don't take my word for it.) -- Tapani Tarvainen (tarvaine@jyu.fi, tarvainen@finjyu.bitnet)