mtl-aas/stl/smooth_robustness.py
2016-12-10 13:38:41 -08:00

72 lines
1.6 KiB
Python

# TODO: technically incorrect on 0 robustness since conflates < and >
from functools import singledispatch
import sympy as sym
from numpy import arange
from funcy import pairwise, autocurry
import stl.ast
from stl.ast import t_sym
from stl.robustness import op_lookup
@singledispatch
def smooth_robustness(stl, L, h):
raise NotImplementedError
@smooth_robustness.register(stl.And)
@smooth_robustness.register(stl.G)
def _(stl, L, H):
raise NotImplementedError("Call canonicalization function")
def soft_max(rs, eps=0.1):
B = 10
return sym.log(sum(B**r for r in rs), B)
def LSE(rs, eps=0.1):
B = 10
return soft_max(rs) - sym.log(len(rs), B)
@smooth_robustness.register(stl.Or)
def _(stl, L, h):
rl, rh = list(zip(
*[smooth_robustness(arg, L, h) for arg in stl.args]))
return soft_max(rl), LSE(rh)
@autocurry
def x_ij(L, h, xi_xj):
x_i, x_j = xi_xj
return (L*h + x_i + x_j)/2
@smooth_robustness.register(stl.F)
def _(stl, L, H):
lo, hi = stl.interval
times = arange(lo, hi, H)
rl, rh = smooth_robustness(stl.arg, L, H)
los, his = zip(*[(rl.subs({t_sym: t_sym + t}), rh.subs({t_sym: t_sym + t})) for t in times])
return LSE(los), soft_max(map(x_ij(L, H), pairwise(his)))
@smooth_robustness.register(stl.Neg)
def _(stl, L, H):
rl, rh = smooth_robustness(arg, L, H)
return -rh, -rl
@smooth_robustness.register(stl.LinEq)
def _(stl, L, H):
op = op_lookup[stl.op]
retval = op(eval_terms(stl), stl.const)
return retval, retval
def eval_terms(lineq):
return sum(map(eval_term, lineq.terms))
def eval_term(term):
return term.coeff*sym.Function(term.id.name)(t_sym)