v2.1 - Curl operator (matrix) and arbitrary nodal derivatives

What's Changed

• Sync dev with master by @jcorbino in #20
• Add Curl operator, nth-order nodal derivatives, and fix nodal3DCurv bug by @jcorbino in #21

Full Changelog: v2.0...v2.1

v2.0 - Mixed Boundary Conditions, nth-Order Nodal Derivatives & Electromagnetics Examples

New Operators

• Mixed Boundary Conditions (MATLAB & C++): Added mixedBC, mixedBC2D, and mixedBC3D in both MATLAB and C++, implementing Robin-type combinations of Dirichlet and Neumann boundary conditions. A convenience operator+(Laplacian, MixedBC) is exposed in the C++ API.
• nth-Order Nodal Derivatives (MATLAB): nodal, nodal2D, nodal3D, nodal2DCurv, and nodal3DCurv now accept an optional parameter nu to compute the nu-th derivative (default: 1).

New Examples

• Electromagnetics suite: 1D and 2D Maxwell equations (free space and UPML absorbing boundaries) in both MATLAB and C++.
• FDTD vs. Mimetics comparison: Side-by-side implementations of 5 examples from Sullivan's FDTD textbook under examples_MATLAB/Electromagnetics/.
• Numerical integration: New 1D mimetic integration example.
• Time-stepping: Added forward_euler.m for completeness alongside the existing backward Euler example.
• Burgers' equation: Refactored for stability with adaptive CFL timestep and cleaner conservative-form notation.

Bug Fixes

• Fixed argument ordering in mixedBC2D, mixedBC3D (MATLAB) and the C++ MixedBC 2D/3D constructors where top/bottom boundary operators were being passed in the wrong order.

Tests

• Added test6.m covering the new mixedBC/mixedBC3D operators; run_tests.m updated accordingly.

Documentation

• Added Integration by Parts, Divergence Theorem, and Mimetics reference PDF.
• Updated README.md with a 2D Ez field simulation animation, refreshed badges, and cleaned up citation section.

CI

• Fixed intermittent CI failures by adding apt-get update before package installation in the build workflow.

v1.0

What's Changed

• 2D Curvilinear gradient by @jcorbino in #1
• 2D Curv Div by @jcorbino in #2
• Minimal 2D Grid generation based on Transfinite Interpolation by @jcorbino in #3
• 3D Curvilinear grad with basic test by @jcorbino in #4
• Added 3D Curvilinear Divergence by @jcorbino in #5
• Develop by @jcorbino in #10
• [joss review] Update Makefiles by @victorapm in #14
• JOSS copy edits by @jedbrown in #18

New Contributors

• @victorapm made their first contribution in #14
• @jedbrown made their first contribution in #18

Full Changelog: https://github.com/jcorbino/mole/commits/v1.0