GMGPolar v2.0.0

1. Enhancements and New Class Layout:

• Linear Algebra:
  • Introduced custom Vector and SparseMatrix classes.
  • Added a (cyclic) Tridiagonal Solver for improved performance and usability.
• Input Functions:
  • Separated into distinct components: DomainGeometry, BoundaryConditions, SourceTerm, etc.
• Polar Grid:
  • Indexing is now based on circle/radial smoother.
• Residual:
  • Improved the residual calculation by addressing the unintuitive behavior that previously applied only to the interior part of the matrix.
• Direct Solver:
  • Fixed a bug where boundary values were not treated correctly.
  • Built matrices to be symmetric, reducing factorization time.
• Smoother:
  • Separated into extrapolated and standard smoothers.
  • Replaced the LU-Decomposition algorithm with the Thomas algorithm for improved efficiency.

2. New Features

• Introduced W- and F cycles for enhanced solving capabilities.
• Added FMG (Full Multigrid) to obtain improved starting solutions.
• Implemented advanced caching behavior options for the "Give" implementation strategy.
• Added a faster strategy named 'Take,' which is appropriate for cases where memory is less of a constraint, resulting in an 80% increase in memory usage.
• Comprehensive Unit Tests: Integrated Google Unit Tests for all classes, ensuring robust and reliable functionality across the codebase.

3. Performance Improvements

• Removed the task-based approach, which did not scale well with increasing parallelization.
• Reduced maximum usage by 61.5% by constructing symmetric matrices and utilizing the tridiagonal structure of smoother matrices.

4. Updated Features

• Added a new LU decomposition solver, allowing users to choose between MUMPS and the in-house solver for greater flexibility and performance.