def index(self, p):
idx = 0
iwidth = self.bits * self.dimension
for i in range(iwidth):
bitoff = self.bits-(i/self.dimension)-1
poff = self.dimension-(i%self.dimension)-1
b = utils.bitrange(p[poff], self.bits, bitoff, bitoff+1) << i
idx |= b
return utils.igraycode(idx)
def hilbert_index(dimension, order, p):
h, e, d = 0, 0, 0
for i in range(order):
l = 0
for x in range(dimension):
b = utils.bitrange(p[dimension - x - 1], order, i, i + 1)
l |= b << x
l = transform(e, d, dimension, l)
w = utils.igraycode(l)
e = e ^ utils.lrot(entry(w), d + 1, dimension)
d = (d + direction(w, dimension) + 1) % dimension
h = (h << dimension) | w
return h
def hilbert_index(dimension, order, p):
h, e, d = 0, 0, 0
for i in range(order):
l = 0
for x in range(dimension):
b = utils.bitrange(p[dimension - x - 1], order, i, i + 1)
l |= b << x
l = transform(e, d, dimension, l)
w = utils.igraycode(l)
e = e ^ utils.lrot(entry(w), d + 1, dimension)
d = (d + direction(w, dimension) + 1) % dimension
h = (h << dimension) | w
return h
def hilbert_index(dimension, order, p):
# Hamilton's paper initialises d to 0, which appears to be an error.
h, e, d = 0, 0, 1
for i in range(order):
l = 0
for x in range(dimension):
b = utils.bitrange(p[x], order, i, i+1)
l |= b<<x
l = transform(e, d, dimension, l)
w = utils.igraycode(l)
e = e ^ utils.lrot(entry(w), d+1, dimension)
d = (d + direction(w, dimension) + 1)%dimension
h = (h<<dimension)|w
return h
def test_igraycode(self):
for i in range(10):
assert utils.igraycode(utils.graycode(i)) == i
assert utils.graycode(utils.igraycode(i)) == i
def test_igraycode(self):
for i in range(10):
assert utils.igraycode(utils.graycode(i)) == i
assert utils.graycode(utils.igraycode(i)) == i
