Re: Odd [math] behavior
This WebDNA talk-list message is from 2003
It keeps the original formatting.
numero = 52778
interpreted = N
texte = I cringed when I saw this thread, knowing that it would lead to a discussionof the inaccuracies of binary representation of decimal numbers.I got a kick out of the following quote (taken from one of the links Johnprovided - Thanks, John!)."Floating point is by its nature inexact. It is probably best if youimagined that after every floating point operation, a little demon came inand added or subtracted a tiny number to fuzz the low order bits of yourresult..."I am sure that even the most experienced programmer has gotten 'bit' bythis.So, I think the lesson here is to ALWAYS keep in mind the desired'precision' when performing floating point arithmetic and use the [formatx.xf] to ensure that you get what you expect.FEEDBACK REQUEST: Given that most WebDNA programmers would not expect tohave to deal with those 'fuzzy' low order bits, perhaps we should build in amore user-friendly default precision for the MATH context. Maybe have itcontrolled via a new WebDNA pref? Any thoughts?-----Original Message-----From: John Peacock [mailto:jpeacock@rowman.com]Sent: Thursday, September 11, 2003 12:23 PMTo: WebDNA-Talk@talk.smithmicro.comSubject: Re: Odd [math] behaviourPaul Willis wrote:> I fully agree, I don't understand why any calculations or formattingare> required. This is simple subtraction. 6000.4-5300.3 is 700.1 a small> child could do it.>Unfortunately, computers are far stupider than even the smallest child.Theadvantage of using a computer over a child is that the computer actuallydoeswhat you tell it to do and does it quickly (no "In a minute Daddy!").A quick Google yielded a few useful pages:http://www.python.org/doc/current/tut/node14.htmlhttp://mindprod.com/jgloss/floatingpoint.htmlhttp://www.rwc.uc.edu/koehler/comath/14.htmlHTHJohn--John PeacockDirector of Information Research and TechnologyRowman & Littlefield Publishing Group4501 Forbes BoulevardSuite HLanham, MD 20706301-459-3366 x.5010fax 301-429-5748-------------------------------------------------------------This message is sent to you because you are subscribed to the mailing list
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I cringed when I saw this thread, knowing that it would lead to a discussionof the inaccuracies of binary representation of decimal numbers.I got a kick out of the following quote (taken from one of the links Johnprovided - Thanks, John!)."Floating point is by its nature inexact. It is probably best if youimagined that after every floating point operation, a little demon came inand added or subtracted a tiny number to fuzz the low order bits of yourresult..."I am sure that even the most experienced programmer has gotten 'bit' bythis.So, I think the lesson here is to ALWAYS keep in mind the desired'precision' when performing floating point arithmetic and use the [formatx.xf] to ensure that you get what you expect.FEEDBACK REQUEST: Given that most WebDNA programmers would not expect tohave to deal with those 'fuzzy' low order bits, perhaps we should build in amore user-friendly default precision for the MATH context. Maybe have itcontrolled via a new WebDNA pref? Any thoughts?-----Original Message-----From: John Peacock [mailto:jpeacock@rowman.com]Sent: Thursday, September 11, 2003 12:23 PMTo: WebDNA-Talk@talk.smithmicro.comSubject: Re: Odd [math] behaviourPaul Willis wrote:> I fully agree, I don't understand why any calculations or formattingare> required. This is simple subtraction. 6000.4-5300.3 is 700.1 a small> child could do it.>Unfortunately, computers are far stupider than even the smallest child.Theadvantage of using a computer over a child is that the computer actuallydoeswhat you tell it to do and does it quickly (no "In a minute Daddy!").A quick Google yielded a few useful pages:http://www.python.org/doc/current/tut/node14.htmlhttp://mindprod.com/jgloss/floatingpoint.htmlhttp://www.rwc.uc.edu/koehler/comath/14.htmlHTHJohn--John PeacockDirector of Information Research and TechnologyRowman & Littlefield Publishing Group4501 Forbes BoulevardSuite HLanham, MD 20706301-459-3366 x.5010fax 301-429-5748-------------------------------------------------------------This message is sent to you because you are subscribed to the mailing list .To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail toWeb Archive of this list is at: http://webdna.smithmicro.com/-------------------------------------------------------------This message is sent to you because you are subscribed to the mailing list .To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Web Archive of this list is at: http://webdna.smithmicro.com/
"Scott Anderson"
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