go go go
first go at the wind stuff
add models, solver etc
cython take2. much simpler, still v fast.
don't need pxd file actually
mega fast excellent speed
use cast's shape arg to make code even nicer
remember to cdef _all_ the lerp intermediates
roll up interpolation
optimise solver's results storage
don't need __del__, that will all de-scope automatically
don't actually need those prototypes either
closure over (models, dataset) on models.f
closure over any(terminator)
s/t/term/
use list of (f, term)s
add descent models
add time-based termination
tidy up stuff
oops. need to break in the pressure loop