def test_subtract_zero_drift(self):
N = 10
drift = DataFrame(np.zeros((N - 1, 2)),
index=np.arange(1, N)).astype('float64')
drift.columns = ['x', 'y']
drift.index.name = 'frame'
actual = mr.subtract_drift(self.dead_still, drift)
assert_frame_equal(actual, self.dead_still)
actual = mr.subtract_drift(self.many_walks, drift)
assert_frame_equal(actual, self.many_walks)
actual = mr.subtract_drift(self.steppers, drift)
assert_frame_equal(actual, self.steppers)
def test_subtract_constant_drift(self):
N = 10
# Add a constant drift here, and then use subtract_drift to
# subtract it.
drift = DataFrame(np.outer(np.arange(N - 1), [1, 1]),
index=np.arange(1, N))
drift.columns = ['x', 'y']
drift.index.name = 'frame'
actual = mr.subtract_drift(
self.dead_still.add(drift, fill_value=0), drift)
assert_frame_equal(actual, self.dead_still)
actual = mr.subtract_drift(
self.many_walks.add(drift, fill_value=0), drift)
assert_frame_equal(actual, self.many_walks)
actual = mr.subtract_drift(
self.steppers.add(drift, fill_value=0), drift)
assert_frame_equal(actual, self.steppers)