	Related Topics:
	Alter Parameters Without Recalculation

Alter One Parameter and Recalculate

The Alter One Parameter and Recalculate feature enables you to experiment with possible alternative scenarios by allowing you to manually alter one of the parameter values and then have the software estimate the other parameter values that would result in a good fit for the distribution. The ranks and the likelihood function are assumed to remain the same; however, unlike the Alter Parameters without Recalculation method, the Fisher Matrix is evaluated at the altered parameter values. The solution line in the plots and the results in the QCP will be based on the new values of the parameters; therefore, the analysis may be appropriate only within the context of your specific "what-if" analysis.

You can select this option by choosing Life Data > Options > Alter Parameters > Alter One Parameter (And Recalculate).

Note that this feature can be used only with the 2-parameter and the 3-parameter Weibull distributions using MLE. For the 3-parameter Weibull distribution, in order to modify the value of the gamma parameter, and have the software estimate the new values of the other parameters, all three parameters must be estimated using MLE. To enable the setting, select the Use True 3-P MLE on Weibull check box in the Calculations page of the Application Setup. Note that the pure MLE solution is not always stable, and may fail for some data sets.