Re: MemberQ
- To: mathgroup at smc.vnet.net
- Subject: [mg68524] Re: [mg68503] MemberQ
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Wed, 9 Aug 2006 04:18:24 -0400 (EDT)
- Organization: Mathematics & Statistics, Univ. of Mass./Amherst
- References: <200608081028.GAA29635@smc.vnet.net>
- Reply-to: murray at math.umass.edu
- Sender: owner-wri-mathgroup at wolfram.com
Roundoff error? Remember that decimals are converted to, and
manipulated arithmetically as binary, then converted back. Look at this:
$Version
5.2 for Microsoft Windows (June 20, 2005)
$MachinePrecision
15.9546
NumberForm[Range[0., 1., .1], 16]
{0.,0.1,0.2,0.3,0.4,0.5,0.6000000000000001,0.7000000000000001,0.8,0.9,1.}
NumberForm[.7, 16]
0.7
Bruce Colletti wrote:
> Re Mathematica 5.2.0.0.
>
> Since 0.7 is in the set {0.0, 0.1, 0.2,..., 0.9, 1.0}, why does MemberQ[Range[0., 1., .1], .7] return False?
--
Murray Eisenberg murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305
- References:
- MemberQ
- From: Bruce Colletti <vze269bv@verizon.net>
- MemberQ