25.8 Distribution Parameters from Statistical Packages

Sometimes the distributions you want to add to your model are derived from external statistical packages like SAS and Stata. TreeAge Pro provides guidance for how to use those packages' distribution parameters when creating a distribution.

Let's consider a Weibull distribution. SAS and Stata actually use the same form of parameters as TreeAge Pro, but they refer to them with different names. When you enter the Stata parameters as show below, they are "converted" to the native TreeAge Pro parameters, which in this case just copies the same values.

However, if a similar Weibull distribution was generated from the R survreg package, the parameters would be different, so the conversion to native TreeAge Pro parameters would include more complex formulas as shown below.