Add LICENSE.md

CVMix uses v3 of the GNU Lesser General Public License, per LICENSE.md.

Add CMake support

CMake build infrastucture

support for building the CVMix library and the CVMix driver using CMake

Bugfix for v0.97-beta

Previous release mis-applied the stability check -- new logic is easier to follow (and mimics the style of the Monin-Obukhov code)

Add stability check to Ekman limiter

Only apply Ekman limiter in stable buoyancy forcing conditions.

Two minor bug fixes

Fixed two one-line bugs (both were cases of pulling the wrong value out of a derived type). Also updated .travis.yml to use an older distribution of Ubuntu so that we can test the netCDF builds.

Add python 3 support

Also start using TravisCI to ensure everything in reg_tests/ continues to run and that coding standards are maintained

quick update to v0.94-beta

I merged an old version of the branch in the last tag and missed a couple of commits. The fortran code is the same, but the stand-alone driver is built with better error-checking by gfortran

Update interface to Langmuir parameterization

CVMix now supports multiple different implementations of the Langmuir turbulence parameterization -- in addition to the Li et al. (2016) parameterization that was already available, the Reichl et al. (2016) and the Li and Fox-Kemper (2017) parameterizations are also in the code.

Performance enhancement

Replace cvmix_get_kpp_real calls with direct access of datatype:

1. Testing in POP showed no answer changes
2. KPP is ~10% faster than v0.92-beta, and POP overall (with iage as the only tracer module) was ~4% faster
3. POP still runs fastest using native KPP instead of CVMix
   • CVMix is ~60% hit on the KPP runtime and 15% on all of POP (down from 80% and 20%, respectively)

Fix bug in computing derivative

cvmix_math_evaluate_cubic() was not computing the derivative of the cubic polynomial correctly, omitting the coefficients from the quadratic and cubic terms.