DualReal

Overview

DualReal is a MOOSE typedef defined from the MetaPhysicL template class DualNumber. DualNumber takes two template arguments T and D; T represents the "value" type of the DualNumber, e.g. the type of , while D represents the derivative type of the DualNumber, e.g. the type of . MetaPhysicL offers several options for D types, including:

1. NumberArray - C-array as underlying derivative vector storage for data - Fast because of static storage - Inflexible; no storage of indices so no sparse support. Essentially pick a maximum possible storage size and hope for the best. Doesn't work out for many 3D problems or problems with a lot of variables

2. DynamicSparseNumberArray - std::vector as underlying storage for derivative data and indices - Maximum flexibility - Slow because of continual dynamic allocation of memory

3. SemiDynamicSparseNumberArray - std::array as underlying storage for derivative data and indices - Fast because of static storage - Indices storage allows sparse operations and hence flexibility - Avoid looping over the whole size of the std::array by maintaining a dynamic size data member

Currently, MOOSE uses SemiDynamicSparseNumberArray for derivative storage because it is much more flexible than NumberArray and more performant than DynamicSparseNumberArray. The underlying derivative storage array size for SemiDynamicSparseNumberArray can be modified by running configure with the option --with-derivative-size=<n> where <n> is the desired size of the container. By default, MOOSE is configured --with-derivative-size=64.

AD-Related Timings

Stabilized Incompressible Navier Stokes