Re: my lsqnonlin is not working

On 4/21/2015 7:36 PM, pmgbashir2001 wrote:
> Hi every body. I am using initial guess 1e11 and 0.25 for target parameters 2e11 and 0.33. However, lsqnonlin is not working, and message is as follows:
>
> Initial point is a local minimum.
>
> Optimization completed because the size of the gradient at the initial point
> is less than the selected value of the function tolerance.
>
> <stopping criteria details>
>
>
> Optimization completed: The final point is the initial point.
> The first-order optimality measure, 0.000000e+00, is less than
> 1e-4*options.TolFun = 1.000000e-11.
>
> Optimization Metric Options
> relative norm(gradient) = 0.00e+00 1e-4*TolFun = 1e-11 (selected)
>
>
>

I believe that the issue is the huge disparity in scales. Perhaps you
can change your objective function definition to rescale the problem,
something like

  function F = myfun(x)
  x(1) = 1e11*x(1)
  % your code here
  end

Then make x0 = [1,1/4] and see if it helps.

Alan Weiss
MATLAB mathematical toolbox documentation