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Topic: problem with finding equilibrium points of nonlinear system
Replies: 6   Last Post: Mar 13, 2013 9:01 AM

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 Christopher Creutzig Posts: 323 Registered: 2/24/09
Re: problem with finding equilibrium points of nonlinear system
Posted: Mar 13, 2013 9:01 AM

On 08.03.13 20:56, gilraen wrote:
> it give warning:
>
> Warning: The solutions are parametrized by the symbols
>
> It means it cannot be solve analytically.

No, it doesn't. It means that the solution set, as far as it could be
simplified, is not just some known finite amount of points. The system
did find the analytic solution for you, but the analytic solution has a
parameter for which you need to select values if you want individual points.

>> [xs, ys] = solve(x+y==1, 2*x+2*y==2, x, y)
Warning: The solutions are parametrized by the symbols:
z = C_

> In solve at 190

xs =

1 - z

ys =

z

xs and ys are solutions for any complex z, found analytically. (And the
result is the complete solution set.) This tells me much more than if I
just got back ?[1, 0],? although I agree that the presentation is not
particularly nice.

HTH,
Christopher

Date Subject Author
3/8/13 Nasser Abbasi
3/8/13 Nasser Abbasi
3/8/13 Nasser Abbasi
3/13/13 Christopher Creutzig