Template:Using the mixed weibull distribution in Weibull++

Using the Mixed Weibull Distribution in Weibull++
To use the mixed Weibull distribution, simply select the Mixed Weibull Distribution from the Distribution drop down list. You can choose Mixed Weibull distribution with 2, 3, or 4 subpopulations?



Viewing the Calculated Parameters

When using the Mixed Weibull option, the parameters given in the result area apply to different subpopulations. To view the results for a particular subpopulation, select the subpopulation, as shown next.



About the Calculated Parameters

Weibull++ uses the numbers 1, 2, 3 and 4 (or first, second, third and fourth subpopulation) to identify each subpopulation. These are just designations for each subpopulation, and they are ordered based on the value of the scale parameter, $$\eta $$. Since the equation used is additive or:


 * $${{R}_{1,..,S}}(T)=\underset{i=1}{\overset{S}{\mathop \sum }}\,\frac{N}{{e}^{-{{\left( \tfrac{t}{{{\eta }_{i}}} \right)}^}}}$$

the order of the subpopulations which are given the designation 1, 2, 3, or 4 is of no consequence. For consistency, the application will always return the order of the results based on the magnitude of the scale parameter.

Example 1: