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Re: Odd behavior?

  • To: mathgroup at
  • Subject: [mg101862] Re: [mg101850] Odd behavior?
  • From: "David Park" <djmpark at>
  • Date: Mon, 20 Jul 2009 06:00:12 -0400 (EDT)
  • References: <7446401.1248002775990.JavaMail.root@n11>

Try Chop?

David Park
djmpark at  

From: elliot [mailto:esadlon at] 

The expression 5.1 - 4.5 - 0.6 gives different answers depending on the
version of Mathematica. Version 6 says 0. (which is obviously what we
expect) with an accuracy of about 307. Version 7 says -3.33067x10^-16 with
an accuracy of about 31. Also, in version 7, if the expression is changed to
5.1 - (4.5 + 0.6) the answer it gives is 0. with an accuracy of about 307.
Both versions were run on three different computers.

Anybody know what changed or what I can do to prevent such poor solutions
(besides forcing a specific order of evaluation)? Thanks.

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