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The Convergence Parameters Dialogue

Use the Convergence Parameters dialogue to set the conditions under which the fit will terminate. It is rarely useful to change these settings from their default values and doing so is not recommended. You may set the following values.

Function Evaluation Limit
The maximum number of times that tex2html_wrap_inline1943 may be evaluated, ignoring evaluations for determining gradients and the curvature matrix.

Iteration Limit
The maximum number of iterations to be performed. Note that convergence will usually only take 10 to 20 iterations if the starting model is reasonable.

Relative Function Convergence Tolerance
The largest relative change in tex2html_wrap_inline1943 that will be accepted as showing that the process has converged. Other criteria must also be met so that the program is sure that a true minimum has been reached. Larger values (less than unity) are less stringent but raising this value is rarely effective.

X-Convergence Tolerance
The distance in scaled parameter space that is used to test whether the parameters are close enough to their optimum values for the process to have converged. The scaling factors vary dynamically during the fit so this value can not be set from a set of accuracy requirements. Large numbers are less stringent.

False Convergence Tolerance
A parameter used in the false convergence test. Smaller numbers make false convergence less likely but the default value is only 100 times the machine precision, giving little scope for significant reductions.

Click on OK or Apply to make any changes take effect. The dialogue will be dismissed if you click on OK but will remain in place if you click on Apply.

Click on Cancel to dismiss the dialogue without changing the convergence parameters.



Chris Flatters
Thu Mar 14 16:02:50 MST 1996