def vwr(self, attr):
'''Return the Visvalingam-Whyatt results, optionally
including the triangular area (in meters) as
attribute attr to each simplified point.
'''
pts, r = self.pts, self.r
# double check the minimal triangular area
assert min(t2.h2 for t2 in r) > self.s2 > 0
if attr: # return the trangular area (actually
# the sqrt of double the triangular area)
# converted back from degrees to meter
if isNumpy2(pts):
raise AttributeError('%r invalid' % (attr,))
m = radians(1.0) * self.radius
r[0].h2 = r[-1].h2 = 0 # zap sentinels
for t2 in r: # convert back to meter
setattr(pts[t2.ix], attr, sqrt(t2.h2) * m)
# double check for duplicates
n = len(r)
r = dict((t2.ix, True) for t2 in r)
assert len(r) == n
return self.points(r)
def points(self, r):
'''Return the list of simplified points or indices.
'''
r = sorted(r.keys())
if self.indices:
return list(r)
elif isNumpy2(self.pts) or isTuple2(self.pts):
return self.pts.subset(r)
else:
return [self.pts[i] for i in r]