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MatrixReplace.m

• To: mathgroup at smc.vnet.net
• Subject: [mg25001] MatrixReplace.m
• From: Giovanni Scoglio <g_scoglio at yahoo.it>
• Date: Fri, 1 Sep 2000 01:09:34 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

Hi everybody

Roger Kirchner in MatrixReplace.m
(http://mathsource.wri.com/Content/Enhancements/Algebraic/0202-284)
says : 

" MatrixReplace[f[x], x -> A] returns f[A], where
multiplication
  is matrix multiplication. "

Well, let mat = {{1, 2}, {2, 3}}

MatrixPower[mat, 3] gives
{{21, 34}, {34, 55}} :-)

and 1 + MatrixPower[mat, 3] gives
{{22, 35}, {35, 56}} :-)

Why does MatrixReplace[1 + x^3, x -> mat] return
{{22, 34}, {34, 56}} instead ? :-(

It this a bug ? Is there something unclear to me in
the concept of matrix function ?

Buon lavoro a tutti !
Giovanni Scoglio

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