From: Karl Dubost <karl@w3.org>

Date: Wed, 21 Nov 2007 19:51:36 +0900

Message-Id: <D8776C3B-6764-4241-8DF6-7C01C7BF7B4A@w3.org>

To: www-svg@w3.org

Date: Wed, 21 Nov 2007 19:51:36 +0900

Message-Id: <D8776C3B-6764-4241-8DF6-7C01C7BF7B4A@w3.org>

To: www-svg@w3.org

For Information The trouble with matrix multiplication 2007-11-19 is that it’s not commutative. That means that when the SVG spec says in the documentation for the multiply method in the SVGMatrix DOM “this matrix is post-multiplied by another matrix” it really does matter which way round you do the multiplication of the two matrices. In the call «A.multiply(B)», A is this and should be post-multiplied by B. In the usual mathematical convention the result should be AB. Safari computes BA, Firefox computes AB. Oopsy. -- The trouble with matrix multiplication « code monk http://drj11.wordpress.com/2007/11/19/the-trouble-with-matrix-multiplication/ Wed, 21 Nov 2007 10:50:19 GMT -- Karl Dubost - W3C http://www.w3.org/QA/ Be Strict To Be CoolReceived on Wednesday, 21 November 2007 10:51:49 UTC

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