From ... From: Erik Naggum Subject: Re: best CL type for fixed decimal values Date: 2000/03/03 Message-ID: <3161081269457609@naggum.no>#1/1 X-Deja-AN: 592685699 References: <841E799D01879E00.B3B5EAAA6E7974E3.74A6C500761082CD@lp.airnews.net> mail-copies-to: never Content-Type: text/plain; charset=us-ascii X-Complaints-To: newsmaster@eunet.no X-Trace: oslo-nntp.eunet.no 952094477 23977 195.0.192.66 (3 Mar 2000 14:41:17 GMT) Organization: Naggum Software; vox: +47 8800 8879; fax: +47 8800 8601; http://www.naggum.no User-Agent: Gnus/5.0803 (Gnus v5.8.3) Emacs/20.5 Mime-Version: 1.0 NNTP-Posting-Date: 3 Mar 2000 14:41:17 GMT Newsgroups: comp.lang.lisp * Marc Battyani | What CL types are best suited for computing with fixed decimal values with | exactly n places after the decimal point? | | I can use | floats with a special rounding after each operation * Johan Kullstam | floats are out since finite length decimal point numbers often have | non-finite binary expansions. 0.1 for example cannot be represented | exactly by floating point. but if he knows he has N places after the decimal point, that translates directly to a factor (expt 10 N), which means he could do well with the extra precision and speed of a double-float value relative to bignums. #:Erik