def run_aharm_sampler():
for seed in [733] + list(range(10)):
print()
print("SEED=%d" % seed)
print()
np.random.seed(seed)
nsteps = max(1, int(10**np.random.uniform(0, 3)))
Nlive = int(10**np.random.uniform(1.5, 3))
print("Nlive=%d nsteps=%d" % (Nlive, nsteps))
sampler = AHARMSampler(nsteps, adaptive_nsteps=False, region_filter=False)
us = np.random.uniform(0.6, 0.8, size=(4000, 2))
Ls = loglike_vectorized(us)
i = np.argsort(Ls)[-Nlive:]
us = us[i,:]
Ls = Ls[i]
Lmin = Ls.min()
transformLayer = ScalingLayer()
transformLayer.optimize(us, us)
region = MLFriends(us, transformLayer)
region.maxradiussq, region.enlarge = region.compute_enlargement()
region.create_ellipsoid()
nfunccalls = 0
ncalls = 0
while True:
u, p, L, nc = sampler.__next__(region, Lmin, us, Ls, transform, loglike)
nfunccalls += 1
ncalls += nc
if u is not None:
break
if nfunccalls > 100 + nsteps:
assert False, ('infinite loop?', seed, nsteps, Nlive)
print("done in %d function calls, %d likelihood evals" % (nfunccalls, ncalls))
def test_aharm_sampler():
def loglike(theta):
return -0.5 * (((theta - 0.5)/0.01)**2).sum(axis=1)
def transform(x):
return x
seed = 1
Nlive = 10
np.random.seed(seed)
us = np.random.uniform(size=(Nlive, 2))
Ls = loglike(us)
Lmin = Ls.min()
transformLayer = ScalingLayer()
transformLayer.optimize(us, us)
region = MLFriends(us, transformLayer)
region.maxradiussq, region.enlarge = region.compute_enlargement()
region.create_ellipsoid()
assert region.inside(us).all()
nsteps = 10
sampler = AHARMSampler(nsteps=nsteps, region_filter=True)
nfunccalls = 0
ncalls = 0
while True:
u, p, L, nc = sampler.__next__(region, Lmin, us, Ls, transform, loglike)
nfunccalls += 1
ncalls += nc
if u is not None:
break
if nfunccalls > 100 + nsteps:
assert False, ('infinite loop?', seed, nsteps, Nlive)
print("done in %d function calls, %d likelihood evals" % (nfunccalls, ncalls))
def test_region_sampling_scaling(plot=False):
np.random.seed(1)
upoints = np.random.uniform(0.2, 0.5, size=(1000, 2))
upoints[:, 1] *= 0.1
transformLayer = ScalingLayer(wrapped_dims=[])
transformLayer.optimize(upoints, upoints)
region = MLFriends(upoints, transformLayer)
region.maxradiussq, region.enlarge = region.compute_enlargement(
nbootstraps=30)
print("enlargement factor:", region.enlarge, 1 / region.enlarge)
region.create_ellipsoid()
nclusters = transformLayer.nclusters
assert nclusters == 1
assert np.allclose(region.unormed, region.transformLayer.transform(
upoints)), "transform should be reproducible"
assert region.inside(
upoints).all(), "live points should lie near live points"
if plot:
plt.plot(upoints[:, 0], upoints[:, 1], 'x ')
for method in region.sampling_methods:
points, nc = method(nsamples=400)
plt.plot(points[:, 0],
points[:, 1],
'o ',
label=str(method.__name__))
plt.legend(loc='best')
plt.savefig('test_regionsampling_scaling.pdf', bbox_inches='tight')
plt.close()
for method in region.sampling_methods:
print("sampling_method:", method)
newpoints = method(nsamples=4000)
lo1, lo2 = newpoints.min(axis=0)
hi1, hi2 = newpoints.max(axis=0)
assert 0.15 < lo1 < 0.25, (method.__name__, newpoints, lo1, hi1, lo2,
hi2)
assert 0.015 < lo2 < 0.025, (method.__name__, newpoints, lo1, hi1, lo2,
hi2)
assert 0.45 < hi1 < 0.55, (method.__name__, newpoints, lo1, hi1, lo2,
hi2)
assert 0.045 < hi2 < 0.055, (method.__name__, newpoints, lo1, hi1, lo2,
hi2)
assert region.inside(newpoints).mean() > 0.99, region.inside(
newpoints).mean()
region.maxradiussq = 1e-90
assert np.allclose(region.unormed, region.transformLayer.transform(
upoints)), "transform should be reproducible"
assert region.inside(
upoints).all(), "live points should lie very near themselves"
def test_transform():
np.random.seed(1)
corrs = np.arange(-1, 1, 0.1)
corrs *= 0.999
for corr in corrs:
for scaleratio in [1, 0.001]:
covmatrix = np.array([[1., corr], [corr, 1.]])
points = np.random.multivariate_normal(np.zeros(2),
covmatrix,
size=1000)
print(corr, scaleratio, covmatrix.flatten(), points.shape)
points[:, 0] = points[:, 0] * 0.01 * scaleratio + 0.5
points[:, 1] = points[:, 1] * 0.01 + 0.5
layer = ScalingLayer()
layer.optimize(points, points)
tpoints = layer.transform(points)
assert tpoints.shape == points.shape, (tpoints.shape, points.shape)
points2 = layer.untransform(tpoints)
assert tpoints.shape == points2.shape, (tpoints.shape,
points2.shape)
assert (points2 == points).all(), (points, tpoints, points2)
# transform a single point
points = points[0]
tpoints = layer.transform(points)
assert tpoints.shape == points.shape, (tpoints.shape, points.shape)
points2 = layer.untransform(tpoints)
assert tpoints.shape == points2.shape, (tpoints.shape,
points2.shape)
assert (points2 == points).all(), (points, tpoints, points2)
def benchmark_maxradius():
print(" ndim | npts | duration")
for ndim in 2, 4, 8, 16, 32, 64:
plotpoints = []
np.random.seed(ndim)
for npts in 100, 400, 1000, 4000:
points = np.random.uniform(size=(npts, ndim))
transformLayer = ScalingLayer()
region = MLFriends(points, transformLayer)
niter = 0
total_duration = 0
while total_duration < 1:
start = time.time()
maxr = region.compute_maxradiussq(nbootstraps=20)
total_duration += time.time() - start
niter += 1
print('%5d | %5d | %.2fms val=%f' %
(ndim, npts, total_duration * 1000 / niter, maxr))
plotpoints.append((npts, total_duration * 1000 / niter / npts**2))
plt.plot(*zip(*plotpoints), label='ndim=%d' % ndim)
plt.xlabel('Number of live points')
plt.ylabel('Duration [ms] / nlive$^2$')
plt.yscale('log')
plt.xscale('log')
plt.legend(loc='best', prop=dict(size=10))
plt.savefig('testmaxradius.pdf', bbox_inches='tight')
plt.close()
def test_clusteringcase_eggbox():
from ultranest.mlfriends import update_clusters, ScalingLayer, MLFriends
points = np.loadtxt(os.path.join(here, "eggboxregion.txt"))
transformLayer = ScalingLayer()
transformLayer.optimize(points, points)
region = MLFriends(points, transformLayer)
maxr = region.compute_maxradiussq(nbootstraps=30)
assert 1e-10 < maxr < 5e-10
print('maxradius:', maxr)
nclusters, clusteridxs, overlapped_points = update_clusters(
points, points, maxr)
# plt.title('nclusters: %d' % nclusters)
# for i in np.unique(clusteridxs):
# x, y = points[clusteridxs == i].transpose()
# plt.scatter(x, y)
# plt.savefig('testclustering_eggbox.pdf', bbox_inches='tight')
# plt.close()
assert 14 < nclusters < 20, nclusters
def prepare_problem(problemname, ndim, nlive, sampler):
loglike, grad, volume, warmup = get_problem(problemname, ndim=ndim)
if hasattr(sampler, 'set_gradient'):
sampler.set_gradient(grad)
np.random.seed(1)
us = np.random.uniform(size=(nlive, ndim))
if ndim > 1:
transformLayer = AffineLayer()
else:
transformLayer = ScalingLayer()
transformLayer.optimize(us, us)
region = MLFriends(us, transformLayer)
region.maxradiussq, region.enlarge = region.compute_enlargement(
nbootstraps=30)
region.create_ellipsoid(minvol=1.0)
Ls = np.array([loglike(u) for u in us])
ncalls = 0
nok = 0
i = 0
while True:
if i % int(nlive * 0.2) == 0:
minvol = (1 - 1. / nlive)**i
nextTransformLayer = transformLayer.create_new(us,
region.maxradiussq,
minvol=minvol)
nextregion = MLFriends(us, nextTransformLayer)
nextregion.maxradiussq, nextregion.enlarge = nextregion.compute_enlargement(
nbootstraps=30)
if nextregion.estimate_volume() <= region.estimate_volume():
region = nextregion
transformLayer = region.transformLayer
region.create_ellipsoid(minvol=minvol)
# replace lowest likelihood point
j = np.argmin(Ls)
Lmin = float(Ls[j])
while True:
u, v, logl, nc = sampler.__next__(region, Lmin, us, Ls, transform,
loglike)
ncalls += nc
if logl is not None:
break
us[j, :] = u
region.u[j, :] = u
region.unormed[j, :] = region.transformLayer.transform(u)
Ls[j] = logl
i = i + 1
#print(i, Lmin, volume(Lmin, ndim))
if np.isfinite(volume(Lmin, ndim)):
nok += 1
if nok > 2 * nlive + 1000:
break
return region, i, Lmin, us, Ls, transform, loglike
def test_ellipsoid_bracket(plot=False):
for seed in range(20):
print("seed:", seed)
np.random.seed(seed)
if seed % 2 == 0:
us = np.random.normal(size=(2**np.random.randint(3, 10), 2))
us /= ((us**2).sum(axis=1)**0.5).reshape((-1, 1))
us = us * 0.1 + 0.5
else:
us = np.random.uniform(size=(2**np.random.randint(3, 10), 2))
if plot:
import matplotlib.pyplot as plt
plt.plot(us[:, 0], us[:, 1], 'o ', ms=2)
transformLayer = ScalingLayer()
region = MLFriends(us, transformLayer)
try:
region.maxradiussq, region.enlarge = region.compute_enlargement()
region.create_ellipsoid()
except ValueError:
continue
print(region.ellipsoid_center)
print(region.enlarge)
print(region.ellipsoid_cov)
print(region.ellipsoid_invcov)
print(region.ellipsoid_axes)
print(region.ellipsoid_inv_axes)
ucurrent = np.array([2**0.5 * 0.1 / 2 + 0.5, 2**0.5 * 0.1 / 2 + 0.5])
ucurrent = np.array([0.4, 0.525])
v = np.array([1., 0])
if plot: plt.plot(ucurrent[0], ucurrent[1], 'o')
print("from", ucurrent, "in direction", v)
left, right = ellipsoid_bracket(ucurrent, v, region.ellipsoid_center,
region.ellipsoid_inv_axes,
region.enlarge)
uleft = ucurrent + v * left
uright = ucurrent + v * right
if plot:
plt.plot([uleft[0], uright[0]], [uleft[1], uright[1]], 'x-')
plt.savefig('test_ellipsoid_bracket.pdf', bbox_inches='tight')
plt.close()
print("ellipsoid bracket:", left, right)
assert left <= 0, left
assert right >= 0, right
assert_point_touches_ellipsoid(ucurrent, v, left,
region.ellipsoid_center,
region.ellipsoid_invcov, region.enlarge)
assert_point_touches_ellipsoid(ucurrent, v, right,
region.ellipsoid_center,
region.ellipsoid_invcov, region.enlarge)
def make_region(ndim):
us = np.random.uniform(size=(1000, ndim))
if ndim > 1:
transformLayer = AffineLayer()
else:
transformLayer = ScalingLayer()
transformLayer.optimize(us, us)
region = MLFriends(us, transformLayer)
region.maxradiussq, region.enlarge = region.compute_enlargement(
nbootstraps=30)
region.create_ellipsoid(minvol=1.0)
return region
def test_overclustering_eggbox_txt():
from ultranest.mlfriends import update_clusters, ScalingLayer, MLFriends
np.random.seed(1)
for i in [20, 23, 24, 27, 49]:
print()
print("==== TEST CASE %d =====================" % i)
print()
points = np.loadtxt(os.path.join(here, "overclustered_u_%d.txt" % i))
for k in range(3):
transformLayer = ScalingLayer(wrapped_dims=[])
transformLayer.optimize(points, points)
region = MLFriends(points, transformLayer)
maxr = region.compute_maxradiussq(nbootstraps=30)
region.maxradiussq = maxr
nclusters = transformLayer.nclusters
print("manual: r=%e nc=%d" % (region.maxradiussq, nclusters))
# assert 1e-10 < maxr < 5e-10
nclusters, clusteridxs, overlapped_points = update_clusters(
points, points, maxr)
print("reclustered: nc=%d" % (nclusters))
if False:
plt.title('nclusters: %d' % nclusters)
for k in np.unique(clusteridxs):
x, y = points[clusteridxs == k].transpose()
plt.scatter(x, y)
plt.savefig('testoverclustering_eggbox_%d.pdf' % i,
bbox_inches='tight')
plt.close()
assert 14 < nclusters < 20, (nclusters, i)
for j in range(3):
nclusters, clusteridxs, overlapped_points = update_clusters(
points, points, maxr)
assert 14 < nclusters < 20, (nclusters, i)
def test_wrap(plot=False):
np.random.seed(1)
for Npoints in 10, 100, 1000:
for wrapids in [[], [0], [1], [0, 1]]:
print("Npoints=%d wrapped_dims=%s" % (Npoints, wrapids))
#wrapids = np.array(wrapids)
points = np.random.normal(0.5, 0.01, size=(Npoints, 2))
for wrapi in wrapids:
points[:, wrapi] = np.fmod(points[:, wrapi] + 0.5, 1)
assert (points > 0).all(), points
assert (points < 1).all(), points
layer = ScalingLayer(wrapped_dims=wrapids)
layer.optimize(points, points)
tpoints = layer.transform(points)
assert tpoints.shape == points.shape, (tpoints.shape, points.shape)
points2 = layer.untransform(tpoints)
assert tpoints.shape == points2.shape, (tpoints.shape,
points2.shape)
if plot:
plt.subplot(1, 2, 1)
plt.scatter(points[:, 0], points[:, 1])
plt.scatter(points2[:, 0], points2[:, 1], marker='x')
plt.subplot(1, 2, 2)
plt.scatter(tpoints[:, 0], tpoints[:, 1])
plt.savefig("testtransform_%d_wrap%d.pdf" %
(Npoints, len(wrapids)),
bbox_inches='tight')
plt.close()
assert np.allclose(points2, points), (points, tpoints, points2)
layer = AffineLayer(wrapped_dims=wrapids)
layer.optimize(points, points)
tpoints = layer.transform(points)
assert tpoints.shape == points.shape, (tpoints.shape, points.shape)
points2 = layer.untransform(tpoints)
assert tpoints.shape == points2.shape, (tpoints.shape,
points2.shape)
def evaluate_warmed_sampler(problemname,
ndim,
nlive,
nsteps,
sampler,
seed=1,
region_class=RobustEllipsoidRegion):
loglike, grad, volume, warmup = get_problem(problemname, ndim=ndim)
if hasattr(sampler, 'set_gradient'):
sampler.set_gradient(grad)
np.random.seed(seed)
def multi_loglike(xs):
return np.asarray([loglike(x) for x in xs])
us = np.array([warmup(ndim) for i in range(nlive)])
Ls = np.array([loglike(u) for u in us])
vol0 = volume(Ls.min(), ndim)
nwarmup = 3 * nlive
if ndim > 1:
transformLayer = AffineLayer()
else:
transformLayer = ScalingLayer()
transformLayer.optimize(us, us)
region = region_class(us, transformLayer)
region.maxradiussq, region.enlarge = region.compute_enlargement(
nbootstraps=30)
region.create_ellipsoid(minvol=vol0)
assert region.ellipsoid_center is not None
sampler.region_changed(Ls, region)
Lsequence = []
stepsequence = []
ncalls = 0
for i in tqdm.trange(nsteps + nwarmup):
if i % int(nlive * 0.2) == 0:
minvol = (1 - 1. / nlive)**i * vol0
with warnings.catch_warnings(), np.errstate(all='raise'):
try:
nextTransformLayer = transformLayer.create_new(
us, region.maxradiussq, minvol=minvol)
nextregion = region_class(us, nextTransformLayer)
nextregion.maxradiussq, nextregion.enlarge = nextregion.compute_enlargement(
nbootstraps=30)
if isinstance(nextregion, RobustEllipsoidRegion
) or nextregion.estimate_volume(
) <= region.estimate_volume():
nextregion.create_ellipsoid(minvol=minvol)
region = nextregion
transformLayer = region.transformLayer
assert region.ellipsoid_center is not None
sampler.region_changed(Ls, region)
except Warning as w:
print("not updating region because: %s" % w)
except FloatingPointError as e:
print("not updating region because: %s" % e)
except np.linalg.LinAlgError as e:
print("not updating region because: %s" % e)
# replace lowest likelihood point
j = np.argmin(Ls)
Lmin = float(Ls[j])
while True:
u, v, logl, nc = sampler.__next__(region, Lmin, us, Ls, transform,
multi_loglike)
if i > nwarmup:
ncalls += nc
if logl is not None:
assert np.isfinite(u).all(), u
assert np.isfinite(v).all(), v
assert np.isfinite(logl), logl
break
if i > nwarmup:
Lsequence.append(Lmin)
stepsequence.append(quantify_step(us[sampler.starti, :], u))
us[j, :] = u
Ls[j] = logl
Lsequence = np.asarray(Lsequence)
return Lsequence, ncalls, np.array(stepsequence)
def benchmark_transform():
npts = 400
for layer in 'scale', 'affine':
print(" ndim | duration [%s]" % layer)
tplotpoints = []
rplotpoints = []
nplotpoints = []
for ndim in 2, 4, 8, 16, 32, 64, 128, 256, :
np.random.seed(ndim)
points = np.random.uniform(0.4, 0.6, size=(npts, ndim))
transformLayer = ScalingLayer(
) if layer == 'scale' else AffineLayer()
region = MLFriends(points, transformLayer)
region.maxradiussq, region.enlarge = region.compute_enlargement(
nbootstraps=30)
region.create_ellipsoid()
niter = 0
total_duration = 0
while total_duration < .1:
start = time.time()
u = region.transformLayer.untransform(
np.random.normal(size=(ndim)))
region.transformLayer.transform(u)
total_duration += time.time() - start
niter += 1
print('%5d | %.2fms ' % (ndim, total_duration * 1000 / niter))
tplotpoints.append((ndim, total_duration * 1000 / niter))
niter = 0
total_duration = 0
while total_duration < .1:
u = np.random.normal(0.5, 0.1, size=(10, ndim))
start = time.time()
region.inside(u)
total_duration += time.time() - start
niter += 1
print('%5d | %.2fms ' %
(ndim, total_duration * 1000 / niter))
rplotpoints.append((ndim, total_duration * 1000 / niter))
niter = 0
total_duration = 0
while total_duration < .1:
u = np.random.normal(0.5, 0.1, size=(10, ndim))
start = time.time()
array = np.empty((10), dtype=int)
array[:] = -1
array = np.empty((10), dtype=int)
array[:] = -1
array = np.empty((10), dtype=int)
array[:] = -1
total_duration += time.time() - start
niter += 1
print('%5d | %.2fms ' %
(ndim, total_duration * 1000 / niter))
nplotpoints.append((ndim, total_duration * 1000 / niter))
plt.plot(*zip(*tplotpoints), label=layer + ' transform')
plt.plot(*zip(*rplotpoints), label=layer + ' region.inside')
plt.plot(*zip(*nplotpoints), label=layer + ' array')
plt.xlabel('Number of dimensions')
plt.ylabel('Duration [ms]')
plt.yscale('log')
plt.xscale('log')
plt.legend(loc='best', prop=dict(size=10))
plt.savefig('testtransform.pdf', bbox_inches='tight')
plt.close()