Re: Mod bug
- To: mathgroup at smc.vnet.net
- Subject: [mg42838] Re: Mod bug
- From: bobhanlon at aol.com (Bob Hanlon)
- Date: Wed, 30 Jul 2003 19:30:32 -0400 (EDT)
- References: <bg7vh3$hhp$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
You are using inexact numbers and will get inexact results due to machine precision when storing numbers Mod[.5,.1] 0.1 For exact results use exact numbers Mod[1/2,1/10] 0 or Mod[Rationalize[.5],Rationalize[.1]] 0 Union[Table[Mod[x,1/10],{x,1/10,10,1/10}]] {0} Bob Hanlon In article <bg7vh3$hhp$1 at smc.vnet.net>, "frauendorfer" <frauendorfer at perseus.fho-emden.de> wrote: << A program written in version 3 using Mod fails completely in version 4.2 and 5. Checking Mod I found a quite erratic behavior.For example Mod[.5,.1] gives the result 0.1. A list increasing from 0.1 to 10 in 100 steps of 0.1, run through Mod[*,.1] gives 47 wrong answers. >><BR><BR>