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Re: How to set AccuracyGoal and PrecisionGoal?

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  • Subject: [mg70743] Re: [mg70725] How to set AccuracyGoal and PrecisionGoal?
  • From: "Chris Chiasson" <chris at>
  • Date: Wed, 25 Oct 2006 01:40:10 -0400 (EDT)
  • References: <>

This is an example of why we need a control structure that allows one
to add or modify the DownValues of a function without Blocking its
original DownValues.

The reason is that the desired option is difficult to change without
actually changing the default options of FindMinimum.

If the user's routine Aborts in the middle of a computation for which
FindMinimum's default options have been changed, they will remain
changed until the user manually sets them back

-- and now, a response --

Did you give NonlinearRegress a poorly conditioned fitting problem?

One easy way to set the WorkingPrecision option would be to use
SetOptions on FindMinimum before your NonlinearRegress call.

On 10/24/06, Peng Yu <pengyu.ut at> wrote:
> Hi,
> I got the following warning message when I use NonlinearRegress. Could
> you please let me know what I should do if I see this kind of
> warnings?
> FindMinimum::lstol:
>    The line search decreased the step size to within tolerance specified by
>      AccuracyGoal and PrecisionGoal but was unable to find a sufficient
>      decrease in the function.  You may need more than MachinePrecision
>      digits of working precision to meet these tolerances.
> Thanks,
> Peng


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