Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site umn-cs.UUCP Path: utzoo!watmath!clyde!burl!we13!ihnp4!stolaf!umn-cs!herndon From: herndon@umn-cs.UUCP (Robert Herndon) Newsgroups: net.bugs Subject: Prehistoric BC Bug - (nf) Message-ID: <410@umn-cs.UUCP> Date: Tue, 31-Jan-84 21:00:53 EST Article-I.D.: umn-cs.410 Posted: Tue Jan 31 21:00:53 1984 Date-Received: Tue, 7-Feb-84 11:02:14 EST Sender: notes@umn-cs.UUCP Organization: Computer Science Dept., U of Minn, Mpls, MN Lines: 33 #N:umn-cs:1300001:000:745 umn-cs!herndon Jan 31 17:59:00 1984 There is a bug in the BC library. The arc-tangent function ("a") returns pi/4 for the arctangent of any non-zero number. The cause of this is a mis-associated "if" statement in the function definition. The fix for this is to change the definition of the a() function. The file currently reads: 125a126,128 > if(x==1) > if(scale<52) > return(.7853981633974483096156608458198757210492923498437764/1) The following may be substituted: 126,130d125 > if(x==1) { > if(scale<52) { > return(.7853981633974483096156608458198757210492923498437764/1) > } > } Or the lines may be deleted entirely. This will slow down the evaluation of a(1) substantially but will not otherwise harm the function. Robert Herndon umn-cs!herndon