Re: question: re-organising equations

• To: mathgroup at smc.vnet.net
• Subject: [mg55264] Re: [mg55179] question: re-organising equations
• From: yehuda ben-shimol <bsyehuda at gmail.com>
• Date: Thu, 17 Mar 2005 03:31:34 -0500 (EST)
• References: <200503161035.FAA23761@smc.vnet.net>
• Reply-to: yehuda ben-shimol <bsyehuda at gmail.com>
• Sender: owner-wri-mathgroup at wolfram.com

```First, note that in Mathematica notation you should use
x==f[A,B,C,D] to define an equaltiy (unless you work with TradidionalForm)
So I will use that notation here.
you can use pattern matching
myRule = {x -> A, y -> B, z -> C, w -> D, A -> x, B -> y, C -> z, D -> w}
x==f[A,B,C,D]/.myRule
will yield
A == f[x, y, z, w]
as desired
yehuda

On Wed, 16 Mar 2005 05:35:54 -0500 (EST), OneTel
<david.hanson at student.unsw.edu.au> wrote:
>
>
> I have a set of simultaneous equations which are very long and so I will
> not include them here. They take the form of:
>
>     x = f(A,B,C,D)
>     y = f(A,B,C,D)
>     z = f(A,B,C,D)
>     w = f(A,B,C,D)
>
> I would like to re-organise these into the form:
>
>     A = f(x,y,z,w)
>     B = f(x,y,z,w)
>     C = f(x,y,z,w)
>     D = f(x,y,z,w)
>
> May I trouble you for some suggestions as to how this can be achieved?
>
> Thank you,
>
> David Hanson