def test_walkers_dependent_subtle():
nwalkers, ndim = 30, 10
w = np.random.randn(nwalkers, ndim)
assert walkers_independent(w)
# random unit vector
p = np.random.randn(ndim)
p /= np.sqrt(np.dot(p, p))
# project away the direction of p
w -= np.sum(p[None, :] * w, axis=1)[:, None] * p[None, :]
assert not walkers_independent(w)
# shift away from the origin
w += p[None, :]
assert not walkers_independent(w)
def test_walkers_almost_dependent():
nwalkers, ndim = 30, 10
squash = 1e-8
w = np.random.randn(nwalkers, ndim)
assert walkers_independent(w)
# random unit vector
p = np.random.randn(ndim)
p /= np.sqrt(np.dot(p, p))
# project away the direction of p
proj = np.sum(p[None, :] * w, axis=1)[:, None] * p[None, :]
w -= proj
w += squash * proj
assert not walkers_independent(w)
def test_walkers_independent_scaled():
# Some of these scales will overflow if squared, hee hee
scales = np.array([1, 1e10, 1e100, 1e200, 1e-10, 1e-100, 1e-200])
ndim = len(scales)
nwalkers = 5 * ndim
w = np.random.randn(nwalkers, ndim) * scales[None, :]
assert walkers_independent(w)
def test_walkers_independent_randn_offset_longdouble(nwalkers, ndim, offset):
assert walkers_independent(
np.random.randn(nwalkers, ndim) +
np.ones((nwalkers, ndim), dtype=np.longdouble) * offset)
def test_walkers_dependent_big_offset():
nwalkers, ndim = 30, 10
offset = 10 / np.finfo(float).eps
assert not walkers_independent(
np.random.randn(nwalkers, ndim) + np.ones((nwalkers, ndim)) * offset)
def test_walkers_independent_randn_offset(nwalkers, ndim, offset):
assert walkers_independent(
np.random.randn(nwalkers, ndim) + np.ones((nwalkers, ndim)) * offset)
def test_walkers_independent_randn(nwalkers, ndim):
assert walkers_independent(np.random.randn(nwalkers, ndim))
def test_walkers_dependent_toofew(nwalkers, ndim):
assert not walkers_independent(np.random.randn(nwalkers, ndim))
def test_walkers_dependent_ones(nwalkers, ndim):
assert not walkers_independent(np.ones((nwalkers, ndim)))
