Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 5/3/83; site ukc.UUCP Path: utzoo!watmath!clyde!floyd!vax135!ukc!dcw From: dcw@ukc.UUCP (D.C.Wood) Newsgroups: net.bugs Subject: Re: Prehistoric BC Bug - (nf) Message-ID: <4076@ukc.UUCP> Date: Fri, 3-Feb-84 05:44:41 EST Article-I.D.: ukc.4076 Posted: Fri Feb 3 05:44:41 1984 Date-Received: Wed, 8-Feb-84 04:30:43 EST References: <410@umn-cs.UUCP> Organization: Computing Lab. Kent University, England Lines: 27 Here is a Bigger and Better Bug in Bc: scale=99 x=sqrt(2) x 1.414213562373095048801688724209698078569671875376948073176679737990732\ 478462107038850387534327641572 x*x 199999999999999999999999999999999999999999999999999999999999999999999\ 9999999999999999999999999999997921066900256462438170679779231122858093\ 9665738428702231869954990504493272650132450052758957026311840./ x^2 1.999999999999999999999999999999999999999999999999999999999999999999999\ 999999999999999999999999999997 Multiplication can give a relative error of 199(!) orders of magnitude when the scale is greater than 63. Is this a record? Exponetiation gets it right. There may still be a bug in another bc library function - I think it was s() (sine) - which used an undeclared variable `t'. This caused no problems unless it was called from a program which also used `t'. David Wood dcw@ukc.UUCP ...!vax135!ukc!dcw