Re: Lists of Equations
- To: mathgroup at smc.vnet.net
- Subject: [mg106339] Re: Lists of Equations
- From: dh <dh at metrohm.com>
- Date: Fri, 8 Jan 2010 06:28:57 -0500 (EST)
- References: <hi6svt$9uu$1@smc.vnet.net>
Hi Michael,
what you are looking for is: Thread:
yeqs = {y1'[x], y2'[x], y3'[x]};
zeqs = {z1[x], z2[x], z3[x]};
Thread[yeqs == zeqs]
Daniel
Michael Knudsen wrote:
> Hello,
>
> I have just started using Mathematica, and I wonder what the easiest
> way to manage a large set of equations is. I have a bunch of
> differential equations
>
> y1'[x] = z1[x]
> y2'[x] = z2[x]
> ...
> yn'[x] = zn[x]
>
> and I have grouped them together in a list like
>
> eqs = {y1'[x]==z1[x], ..., yn'[x]==zn[x]}
>
> which fits perfectly as an argument to NDSolve. However, I think that,
> at a later point, I may have to use z1,...,zn separately, and I
> thought about defining
>
> yeqs = {y1'[x],...,yn'[x]}
> zeqs = {z1[x],...,zn[x]}
>
> and them combine them. What I would really like is something like
>
> yeqs + "==" + zeqs
>
> but I can't seem to find any list operation that will do that. Any
> help is appreciated.
>
> Thanks,
> Michael Knudsen
>