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Re: info = 3?
From: |
David Bateman |
Subject: |
Re: info = 3? |
Date: |
Sat, 06 Jan 2007 21:46:55 +0100 |
User-agent: |
Thunderbird 1.5.0.7 (X11/20060921) |
huub wrote:
> Hi,
>
> I wrote a function which with fsolve returns info = 3. What does that
> indicate?
>
> function y = wiskunde(x)
> y(1) = 2*x(1) + 2;
> y(2) = 2*x(1).^2 + 3*x(1) + 5;
> endfunction
>
> octave:26> [x, info] = fsolve ("wiskunde", [-5;5])
> x =
>
> -0.76792
> 712.10156
>
> info = 3
>
> Thank you,
>
> Huub
Note fsolve maps minpack info=3,4,5 all to info = 3. From hybrd.f in
minpack (which fsolve uses)
C INFO = 3 XTOL IS TOO SMALL. NO FURTHER IMPROVEMENT IN
C THE APPROXIMATE SOLUTION X IS POSSIBLE.
C
C INFO = 4 ITERATION IS NOT MAKING GOOD PROGRESS, AS
C MEASURED BY THE IMPROVEMENT FROM THE LAST
C FIVE JACOBIAN EVALUATIONS.
C
C INFO = 5 ITERATION IS NOT MAKING GOOD PROGRESS, AS
C MEASURED BY THE IMPROVEMENT FROM THE LAST
C TEN ITERATIONS.
C
So take your pick, all mean that the solution is approximative only...
D.