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Re: MatrixReplace.m


Giovanni,
 1 becomes the 2 by 2 identity matrix
--
Allan
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Allan Hayes
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"Giovanni Scoglio" <g_scoglio at yahoo.it> wrote in message
news:8onep9$ol4 at smc.vnet.net...
> 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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