6.2.1. Optimization in ParAMS 2023.1ΒΆ

Starting with ParAMS 2023.1, the parameter optimization is controlled by GloMPO: Globally Managed Parallel Optimization.

To run a parameter optimization, set Task Optimization in the input file.

You can now run multiple optimizers in parallel. Optimizers converging to bad solutions or otherwise performing badly can be shut off and new ones started. You may configure:

ExitConditions (link)

Stoppers (link)

What does it do?

Stops the entire optimization.

Stops one running optimizer.

What happens once triggered?

The job ends.

Other optimizers are unaffected
and keep running. If possible,
a new optimizer will be started
to replace the stopped one.

When is it evaluated?

Approximately every 10 function
evaluations or more frequently.

This is controlled by the
CheckStopperInterval key.

Am I required to use one?



What is checked?

Generally, global properties
like total time used, or total
function calls made by all

Generally, optimizer specific
properties. Comparisons are often
made between one optimizer and
the best optimizer.

Easy to setup?

Yes. Generally determined by
resource limitations (like time),
or specific goals (like getting
a certain number of results.

Generally, trickier to setup.
Requires problem-specific
information and a good guess
of how optimizers will behave
on the problem.

Good to know?


By default, wont trigger for the
best optimizer unless
ApplyStoppersToBestOptimizer Yes
is used.

The default behavior is to just run a single optimization, as in ParAMS 2022.1. This corresponds to the following input:

    Optimizations 1
    Type MaxOptimizersConverged
    MaxOptimizersConverged 1