def contiguous(self, edge, abs_tol=1E-6, allow_swap=True):
"""
check if edge can be appended to the chain
:param edge: :class:`Entity` to append
:param tol: float tolerance on contiguity
:param allow_swap: if True (default), tries to swap edge or self to find contiguity
:return: int,bool index where to append in chain, swap of edge required
"""
if len(self) == 0: # init the chain with edge
return -1, False
if isclose(self.end.distance(edge.start), 0, abs_tol=abs_tol):
return -1, False # append
if isclose(self.start.distance(edge.end), 0, abs_tol=abs_tol):
return 0, False # prepend
if not allow_swap:
return None, False
if isclose(self.end.distance(edge.end), 0, abs_tol=abs_tol):
return -1, True # append swapped
if isclose(self.start.distance(edge.start), 0, abs_tol=abs_tol):
return 0, True # prepend swapped
return None, False
def chains(group, tol=1E-6, mergeable=None):
"""build chains from all possible segments in group
:param mergeable: function(e1,e2) returning True if entities e1,e2 can be merged
"""
res = Group()
changed = False
# step 1 : add all entities in group to chains in res
for e in group:
if e is None or isclose(e.length, 0, tol):
continue # will not be present in res
for c in res:
# if c.isclosed(): continue #reopen closed chains might be good
if c.append(e, tol=tol, mergeable=mergeable):
changed = True
break
else:
if isinstance(e, Chain):
res.append(e)
else:
res.append(Chain([e]))
# step 2 : try to merge chains
if changed:
res = chains(res, tol, mergeable)
return res
def normal_pdf(x, mu, sigma):
"""Return the probability density function at x"""
try:
return 1. / (math.sqrt(2 * math.pi) * sigma) * math.exp(-0.5 *
(1. / sigma *
(x - mu))**2)
except ZeroDivisionError:
return 1 if math2.isclose(x, mean) else 0
def _switch_points(self, xmin, xmax):
prevy = None
firstpoint, lastpoint = False, False
for x, y in self:
y = y(x)
if x < xmin:
if firstpoint:
continue
firstpoint = True
x = xmin
if x > xmax:
if lastpoint:
break
lastpoint = True
x = xmax
if prevy is not None and not math2.isclose(y, prevy): # step
yield x, prevy
yield x, y
prevy = y
def ishorizontal(self, tol=0.01):
return self.isline() and isclose(self.start.y, self.end.y, tol)
def isvertical(self, tol=0.01):
return self.isline() and isclose(self.start.x, self.end.x, tol)