The HPLMIXED Procedure

The “Convergence Status” table displays the status of the iterative estimation process at the end of the optimization. The status appears as a message in the listing, and this message is repeated in the log. The ODS object “ConvergenceStatus” also contains several nonprinting columns that can be helpful in checking the success of the iterative process, in particular during batch processing. The Status variable takes on the value 0 for a successful convergence (even if the Hessian matrix might not be positive definite). The values 1 and 2 of the Status variable indicate lack of convergence and infeasible initial parameter values, respectively. The variable pdG can be used to check whether the matrix is positive definite.

For models that are not fit iteratively, such as models without random effects or when the NOITER option is in effect, the “Convergence Status” is not produced.