- all branches are added up

boundary conditions can specify how the index list should be built:
- list coordinates of domain or boundary cells (previous always inner)
- list all links or only the first link

- removed warnings from generated code
- made generated code string deterministic, generating the same twice
  gives binary equally files now

- was not used consistently before
- symbol names are expected to be valid C identifiers
- for complicated field names, the latex_name of field should be used

- small (length < 5) arrays with shape and stride information had to be
  memcpy'd to the GPU before every kernel call
- instead of passing the information as arrays, the single elements are
  passed
- leads to more function arguments, but simplifies GPU kernel calls

-> changes in all backends required

- field access are now equal if their underlying fields compare as equal
  not only if the id of their fields are equal

- if a field access is printed in compass or index notation seems to
  depend on the sympy version
- removed doctests that rely on the printed form

- added isotropic version

- new functions to easily extract stencil coefficients and visualize them
- Moved stencil functions from lbmpy to pystencils

- hash function was not correctly implemented
- sometimes this caused a bug where latex version was not correctly displayed

- better latex display for indirect accesses
- new field type 'custom': only custom fields can be accessed indirectly
  no static bounds check possible for custom fields

- different approach in pystencils: absolute indexing

- SSA form is checked
- loop independence condition is checked
- bug fix in Field.create_generic when using index_shape

- flags can be force when setting boundaries, this is helpful for:
- setting up quantities (e.g. relaxation rate..) dependent on current
  flag configuration
- bit operation fix when pickling: function has to have the same name
  as the python object

- removed warnings
- added flake8 as CI target

Jan Hönig authored 7 years ago and Martin Bauer committed 7 years ago

Fixed a bug in field.py

- test run again
- notebooks not yet

- assignment collection
- sympyextensions

- Previously sympy.Eq was used to represent assignments. However Eq
  represents equality not assignment. This means that sometimes sympy
  "simplified" an equation like a = a  to True,
-> replaced sp.Eq by pystencils.Assignment everywhere
- renamed EquationCollection to AssignmentCollection

for fields without index dimensions the indices (0,) and () have been
treated equivalently, but did not compare equal

- step class for LB phasefield generic enough to work with 3-phase and
  N-phase models
- cahn hilliard can either be solved by LBM or by finite differences
- 3 phase model can be solved with rho phase or without

- scaling interface width eta instead of surface tensions tau to correct
  interface profile & surface tensions