Re: operate a matrix of derivations

• To: mathgroup at smc.vnet.net
• Subject: [mg39470] Re: operate a matrix of derivations
• From: Paul Abbott <paul at physics.uwa.edu.au>
• Date: Mon, 17 Feb 2003 18:17:10 -0500 (EST)
• Organization: The University of Western Australia
• References: <b1l15i\$i8o\$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```In article <b1l15i\$i8o\$1 at smc.vnet.net>,
iselig at techunix.technion.ac.il (ilan) wrote:

> I want to make a matrix of derivations, so I will be able to multiply
> it by a matrix of functions and get the result matrix
> simple example:
>
> |d/dx   0 | |xy  x| |y   1|
> |         |.|     |=|     |
> |d/dy d/dx| |x+y 3| |x+1 0|
>
>  thank you

Here is one way. Matrix of operators:

operator = {{D[#, x]& , 0 # & }, {D[#, y]& , D[#, x]& }}

Matrix of functions:

functions = {{x y, x}, {x + y, 3}}

Compose them:

Inner[Compose, operator, functions]

Cheers,
Paul

--
Paul Abbott                                   Phone: +61 8 9380 2734
School of Physics, M013                         Fax: +61 8 9380 1014
The University of Western Australia      (CRICOS Provider No 00126G)
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Crawley WA 6009                      mailto:paul at physics.uwa.edu.au
AUSTRALIA                            http://physics.uwa.edu.au/~paul

```

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