v1.4.0

Changes:

• Add modules for element-wise operations (ElementOperation, Stress, and Strain) (for usage, see the example examples/topology_optimization/ex_volume_stress.py)
• Add density filter based on convolution, allowing 'padded' boundary conditions and custom filtering kernels (for usage, see the example examples/topology_optimization/ex_compliance_padding_filter.py)
• Aggregation modules with active-set and approximation correction strategies
• Rework of linear solvers as a separate package in pyMOTO
• Addition of iterative solver (CG) and several preconditioners (Jacobi, SOR, geometric multigrid)
• Geometric multigrid preconditioner for solving large-scale topology optimization problems (for usage, see the new example examples/topology_optimization/ex_compliance_multigrid.py)
• Several bugfixes and minor improvements

What's Changed

• Convolution filter by @aatmdelissen in #17
• v1.4 release by @aatmdelissen in #19

Full Changelog: v1.3.0...v1.4.0