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Transformation matrix interface - pre-multiply/post-multiply definitions

From: Nikos Andronikos <nikos.andronikos@cisra.canon.com.au>
Date: Fri, 8 Mar 2013 15:06:04 +1100
Message-ID: <513963AC.6090706@cisra.canon.com.au>
To: <public-fx@w3.org>
Hi Dirk,

I was having a look at the Matrix spec [1] and I believe the definitions for pre-multiply and post-multiply are backwards.

>From [1]:
postmultiply
Term B postmultiplied by term A is equal to A  B.

>From wikipedia [2]:
post-multiply (or right multiply) A by C" means AC

Using B and A, as in your text this would give
post-multiply (or right multiply) B by A" means BA

And likewise for pre-multiply.
Could you check please?

Cheers,
Nikos

1: https://dvcs.w3.org/hg/FXTF/raw-file/tip/matrix/index.html
2: http://en.wikipedia.org/wiki/Matrix_multiplication
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Received on Friday, 8 March 2013 04:06:36 GMT

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