mtl-aas/stl/utils.py
2017-11-13 12:44:39 -08:00

134 lines
3 KiB
Python

import operator as op
from functools import reduce
import traces
from lenses import bind
import stl.ast
from stl.ast import (And, F, G, Interval, LinEq, Neg,
Or, AP_lens, Next, Until, AtomicPred,
_Top, _Bot)
from stl.types import STL
oo = float('inf')
def f_neg_or_canonical_form(phi: STL) -> STL:
if isinstance(phi, (LinEq, AtomicPred, _Top, _Bot)):
return phi
children = [f_neg_or_canonical_form(s) for s in phi.children]
if isinstance(phi, (And, G)):
children = [Neg(s) for s in children]
children = tuple(sorted(children, key=str))
if isinstance(phi, Or):
return Or(children)
elif isinstance(phi, And):
return Neg(Or(children))
elif isinstance(phi, Neg):
return Neg(*children)
elif isinstance(phi, Next):
return Next(*children)
elif isinstance(phi, Until):
return Until(*children)
elif isinstance(phi, F):
return F(phi.interval, *children)
elif isinstance(phi, G):
return Neg(F(phi.interval, *children))
else:
raise NotImplementedError
def _lineq_lipschitz(lineq):
return sum(map(abs, bind(lineq).Each().terms.Each().coeff.collect()))
def linear_stl_lipschitz(phi):
"""Infinity norm lipschitz bound of linear inequality predicate."""
return float(max(map(_lineq_lipschitz, phi.lineqs)))
def inline_context(phi, context):
phi2 = None
def update(ap):
return context.get(ap, ap)
while phi2 != phi:
phi2, phi = phi, AP_lens(phi).modify(update)
# TODO: this is hack to flatten the AST. Fix!
return stl.parse(str(phi))
op_lookup = {
">": op.gt,
">=": op.ge,
"<": op.lt,
"<=": op.le,
"=": op.eq,
}
def get_times(x):
times = set.union(*({t for t, _ in v.items()} for v in x.values()))
return sorted(times)
def const_trace(x, start=0):
return traces.TimeSeries([(start, x)], domain=traces.Domain(start, oo))
def eval_lineq(lineq, x, domain, compact=True):
lhs = sum(const_trace(term.coeff)*x[term.id] for term in lineq.terms)
compare = op_lookup.get(lineq.op)
output = lhs.operation(const_trace(lineq.const), compare)
output.domain = domain
if compact:
output.compact()
return output
def eval_lineqs(phi, x):
lineqs = phi.lineqs
start = max(y.domain.start() for y in x.values())
end = min(y.domain.end() for y in x.values())
domain = traces.Domain(start, end)
return {lineq: eval_lineq(lineq, x, domain) for lineq in lineqs}
# EDSL
def alw(phi, *, lo=0, hi=float('inf')):
return G(Interval(lo, hi), phi)
def env(phi, *, lo=0, hi=float('inf')):
return F(Interval(lo, hi), phi)
def andf(*args):
return reduce(op.and_, args) if args else stl.TOP
def orf(*args):
return reduce(op.or_, args) if args else stl.TOP
def implies(x, y):
return ~x | y
def xor(x, y):
return (x | y) & ~(x & y)
def iff(x, y):
return (x & y) | (~x & ~y)
def timed_until(phi, psi, lo, hi):
return env(psi, lo=lo, hi=hi) & alw(stl.ast.Until(phi, psi), lo=0, hi=lo)