Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!ucsd!ucbvax!van-bc!ubc-cs!unixg.ubc.ca!buckland From: buckland@ucs.ubc.ca (Tony Buckland) Newsgroups: comp.lang.fortran Subject: Re: Fortran 90 status Message-ID: <1991May20.174853.25490@unixg.ubc.ca> Date: 20 May 91 17:48:53 GMT References: <23881@lanl.gov> <1991May16.195328.727@casbah.acns.nwu.edu> Sender: news@unixg.ubc.ca (Usenet News Maintenance) Distribution: comp Organization: University of B.C. Computing Services Lines: 19 Nntp-Posting-Host: swiss.ucs.ubc.ca In article jkorpela@vipunen.hut.fi (Jukka Korpela) writes: >The point is that using a real control variable leads to INACCURACIES. >A value such as 0.1 is not reprented exactly on most computers. The >inaccuracy is small but it is ACCUMULATED. Thus the values for which >the loop is actually executed differ from what you probably expect. Several posters have pointed this out. But surely they realize that long-time FORTRAN programmers _know_ about inexact representation of floating-point quantities. They also know that they will, if they use enough decimal places, get results which are good enough. If, to use one poster's example, they want to label plots, they will get good labels to three places if they add an increment vague only in the seventh place. Slide rules were inexact, too. But we still let one another use them; similarly, we should let one another go on applying FORTRAN 77's admirable principle of allowing use of any type which makes sense in the context, one of these contexts being DO control statements.