def toccd(a, newshape, set_total=None):
'''
Clone of oaalib's toccd() function, using least common multiple
to rebin an array similar to opencv's INTER_AREA interpolation.
'''
if a.shape == newshape:
return a
if len(a.shape) != 2:
raise ValueError(
'Input array shape is %s instead of 2d, cannot continue:' %
str(a.shape))
if len(newshape) != 2:
raise ValueError('Output shape is %s instead of 2d, cannot continue' %
str(newshape))
if set_total is None:
set_total = a.sum()
mcmx = lcm(a.shape[0], newshape[0])
mcmy = lcm(a.shape[1], newshape[1])
temp = rebin(a, (mcmx, a.shape[1]), sample=True)
temp = rebin(temp, (newshape[0], a.shape[1]))
temp = rebin(temp, (newshape[0], mcmy), sample=True)
rebinned = rebin(temp, newshape)
return rebinned / rebinned.sum() * set_total
def test_wrong_newshape(self):
a = np.arange(4).reshape((2, 2))
with self.assertRaises(ValueError):
_ = rebin(a, [4, 6, 8])
with self.assertRaises(ValueError):
_ = rebin(a, ['4.0', 6])
def test_newshape_types(self):
a = np.arange(4).reshape((2, 2))
b = rebin(a, [4, 6])
np.testing.assert_array_equal(b, self.ref)
c = rebin(a, map(int, '4 6'.split()))
np.testing.assert_array_equal(c, self.ref)
c = rebin(a, map(int, ['4', 6]))
np.testing.assert_array_equal(c, self.ref)
def test_exceptions(self):
a = np.arange(16).reshape((4, 4))
with self.assertRaises(ValueError):
_ = rebin(a, (7, 7))
with self.assertRaises(ValueError):
_ = rebin(a, (3, 3))
with self.assertRaises(NotImplementedError):
_ = rebin(a, (3, 7))
def test_up_sample(self):
a = np.arange(4).reshape((2, 2))
b = rebin(a, (4, 6), sample=True)
np.testing.assert_array_equal(b, self.ref)