Module circuitgraph.analysis
Functions for analysis of Boolean properties
Expand source code
"""Functions for analysis of Boolean properties"""
from circuitgraph.transform import (
sensitivity_transform,
influence_transform,
sensitization_transform,
)
from circuitgraph.sat import sat, approx_model_count, model_count
from circuitgraph.utils import clog2, int_to_bin
def avg_sensitivity(c, n, approx=True, e=0.9, d=0.1):
"""
Calculates the average sensitivity (equal to total influence)
of node n with respect to its startpoints.
Parameters
----------
c: Circuit
Circuit to compute average sensitivity for.
n : str
Node to compute average sensitivity for.
approx : bool
Use approximate solver
e : float (>0)
epsilon of approxmc
d : float (0-1)
delta of approxmc
Returns
-------
float
Average sensitivity of node n.
"""
sp = c.startpoints(n)
avg_sen = 0
for s in sp:
# create influence circuit
i = influence_transform(c, n, s)
# compute influence
if approx:
mc = approx_model_count(i, {"sat": True}, e=e, d=d)
else:
mc = model_count(i, {"sat": True})
infl = mc / (2 ** len(sp))
avg_sen += infl
return avg_sen
def sensitivity(c, n):
"""
Calculates the sensitivity of node n with respect
to its startpoints.
Parameters
----------
c: Circuit
Circuit to compute sensitivity for
n : str
Node to compute sensitivity for.
Returns
-------
int
Sensitivity of node n.
"""
sp = c.startpoints(n)
if n in sp:
return 1
sen = len(sp)
s = sensitivity_transform(c, n)
vs = int_to_bin(sen, clog2(len(sp)), True)
while not sat(s, {f"sen_out_{i}": v for i, v in enumerate(vs)}):
sen -= 1
vs = int_to_bin(sen, clog2(len(sp)), True)
return sen
def sensitize(c, n, assumptions):
"""
Finds an input that sensitizes n to an endpoint
under assumptions.
Parameters
----------
c: Circuit
Circuit to compute sensitivity for
n : str
Node to compute sensitivity for.
assumptions : dict of str:bool
Assumptions for Circuit.
Returns
-------
dict of str:bool
Input value.
"""
# setup circuit
s = sensitization_transform(c, n)
# find a sensitizing input
result = sat(s, {"sat": True, **assumptions})
if not result:
return None
return {g: result[g] for g in s.startpoints()}
def signal_probability(c, n, approx=True, e=0.9, d=0.1):
"""
Determines the probability of the output being true over all startpoint
combinations
Parameters
----------
c : Circuit
Input circuit.
n : str
Nodes to determine probability for.
approx : bool
Use approximate solver
e : float (>0)
epsilon of approxmc
d : float (0-1)
delta of approxmc
Returns
-------
float
Probability.
"""
# get startpoints not in node fanin
non_fanin_startpoints = c.startpoints() - c.startpoints(n)
# get count with node true and other inputs fixed
assumptions = {g: True for g in non_fanin_startpoints | set([n])}
if approx:
count = approx_model_count(c, assumptions, e=e, d=d)
else:
count = model_count(c, assumptions)
return count / (2 ** len(c.startpoints(n)))Functions
def avg_sensitivity(c, n, approx=True, e=0.9, d=0.1)-
Calculates the average sensitivity (equal to total influence) of node n with respect to its startpoints.
Parameters
c:Circuit- Circuit to compute average sensitivity for.
n:str- Node to compute average sensitivity for.
approx:bool- Use approximate solver
e:float (>0)- epsilon of approxmc
d:float (0-1)- delta of approxmc
Returns
float- Average sensitivity of node n.
Expand source code
def avg_sensitivity(c, n, approx=True, e=0.9, d=0.1): """ Calculates the average sensitivity (equal to total influence) of node n with respect to its startpoints. Parameters ---------- c: Circuit Circuit to compute average sensitivity for. n : str Node to compute average sensitivity for. approx : bool Use approximate solver e : float (>0) epsilon of approxmc d : float (0-1) delta of approxmc Returns ------- float Average sensitivity of node n. """ sp = c.startpoints(n) avg_sen = 0 for s in sp: # create influence circuit i = influence_transform(c, n, s) # compute influence if approx: mc = approx_model_count(i, {"sat": True}, e=e, d=d) else: mc = model_count(i, {"sat": True}) infl = mc / (2 ** len(sp)) avg_sen += infl return avg_sen def sensitivity(c, n)-
Calculates the sensitivity of node n with respect to its startpoints.
Parameters
c:Circuit- Circuit to compute sensitivity for
n:str- Node to compute sensitivity for.
Returns
int- Sensitivity of node n.
Expand source code
def sensitivity(c, n): """ Calculates the sensitivity of node n with respect to its startpoints. Parameters ---------- c: Circuit Circuit to compute sensitivity for n : str Node to compute sensitivity for. Returns ------- int Sensitivity of node n. """ sp = c.startpoints(n) if n in sp: return 1 sen = len(sp) s = sensitivity_transform(c, n) vs = int_to_bin(sen, clog2(len(sp)), True) while not sat(s, {f"sen_out_{i}": v for i, v in enumerate(vs)}): sen -= 1 vs = int_to_bin(sen, clog2(len(sp)), True) return sen def sensitize(c, n, assumptions)-
Finds an input that sensitizes n to an endpoint under assumptions.
Parameters
c:Circuit- Circuit to compute sensitivity for
n:str- Node to compute sensitivity for.
assumptions:dictofstr:bool- Assumptions for Circuit.
Returns
dictofstr:bool- Input value.
Expand source code
def sensitize(c, n, assumptions): """ Finds an input that sensitizes n to an endpoint under assumptions. Parameters ---------- c: Circuit Circuit to compute sensitivity for n : str Node to compute sensitivity for. assumptions : dict of str:bool Assumptions for Circuit. Returns ------- dict of str:bool Input value. """ # setup circuit s = sensitization_transform(c, n) # find a sensitizing input result = sat(s, {"sat": True, **assumptions}) if not result: return None return {g: result[g] for g in s.startpoints()} def signal_probability(c, n, approx=True, e=0.9, d=0.1)-
Determines the probability of the output being true over all startpoint combinations
Parameters
c:Circuit- Input circuit.
n:str- Nodes to determine probability for.
approx:bool- Use approximate solver
e:float (>0)- epsilon of approxmc
d:float (0-1)- delta of approxmc
Returns
float- Probability.
Expand source code
def signal_probability(c, n, approx=True, e=0.9, d=0.1): """ Determines the probability of the output being true over all startpoint combinations Parameters ---------- c : Circuit Input circuit. n : str Nodes to determine probability for. approx : bool Use approximate solver e : float (>0) epsilon of approxmc d : float (0-1) delta of approxmc Returns ------- float Probability. """ # get startpoints not in node fanin non_fanin_startpoints = c.startpoints() - c.startpoints(n) # get count with node true and other inputs fixed assumptions = {g: True for g in non_fanin_startpoints | set([n])} if approx: count = approx_model_count(c, assumptions, e=e, d=d) else: count = model_count(c, assumptions) return count / (2 ** len(c.startpoints(n)))