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[Bug 12705] setTransform spec silent on what to do with singular matrices

From: <bugzilla@jessica.w3.org>
Date: Thu, 19 May 2011 22:16:39 +0000
To: public-html-bugzilla@w3.org
Message-Id: <E1QNBWJ-00027R-10@jessica.w3.org>
http://www.w3.org/Bugs/Public/show_bug.cgi?id=12705

--- Comment #5 from Aryeh Gregor <Simetrical+w3cbug@gmail.com> 2011-05-19 22:16:38 UTC ---
You can *never* rely on equality for floating-point.  Rounding errors mean that
basic mathematical identities don't hold, like (a*b)*c == a*(b*c) or (a/b)*b ==
a.  Having a determinant almost exactly zero wouldn't have to be pathological
at all, it could be any matrix that went through some numeric operations.  For
instance:

data:text/html,<!doctype html><script>alert((10/3000 - 2 + 2)*3000 ==
10)</script>

alerts false in Firefox 4.0, Chrome 12 dev, and Opera 11.10.

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Received on Thursday, 19 May 2011 22:16:40 UTC

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