def get_data_pairs(self, part='train', n=None):
"""
Return first samples from data part as :class:`.DataPairs` object.
Only supports datasets with two elements per sample.``
Parameters
----------
part : {``'train'``, ``'validation'``, ``'test'``}, optional
The data part. Default is ``'train'``.
n : int, optional
Number of pairs (from beginning). If `None`, all available data
is used (the default).
"""
if self.get_num_elements_per_sample() != 2:
raise ValueError(
'`get_data_pairs` only supports datasets with'
'2 elements per sample, this dataset has {:d}'.format(
self.get_num_elements_per_sample()))
gen = self.generator(part=part)
observations, ground_truth = [], []
for obs, gt in islice(gen, n):
observations.append(obs)
ground_truth.append(gt)
name = '{} part{}'.format(part,
' 0:{:d}'.format(n) if n is not None else '')
data_pairs = DataPairs(observations, ground_truth, name=name)
return data_pairs
def test_option_save_iterates(self):
domain = odl.uniform_discr([0, 0], [1, 1], (1, 1))
ground_truth = domain.one()
observation = domain.one()
# reconstruct 1., iterates 0., 0.5, 0.75, 0.875, ...
class DummyReconstructor(StandardIterativeReconstructor):
def _setup(self, observation):
self.setup_var = 'dummy_val'
def _compute_iterate(self, observation, reco_previous, out):
out[:] = 0.5 * (observation + reco_previous)
test_data = DataPairs([observation], [ground_truth])
tt = TaskTable()
r = DummyReconstructor(reco_space=domain)
hyper_param_choices = {'iterations': [10]}
options = {'save_iterates': True}
tt.append(r, test_data, hyper_param_choices=hyper_param_choices,
options=options)
results = tt.run()
self.assertAlmostEqual(
1., results.results['misc'][0, 0]['iterates'][0][2][0, 0],
delta=0.2)
self.assertNotAlmostEqual(
1., results.results['misc'][0, 0]['iterates'][0][1][0, 0],
delta=0.2)
def test_option_save_best_reconstructor_reuse_iterates(self):
# test 'save_best_reconstructor' option together with 'iterations' in
# hyper_param_choices, because `run` has performance optimization for
# it (with the default argument ``reuse_iterates=True``)
domain = odl.uniform_discr([0, 0], [1, 1], (2, 2))
ground_truth = domain.element([[1, 0], [0, 1]])
observation = domain.element([[0, 0], [0, 0]])
# Reconstruct [[1, 0], [0, 1]], iterates are
# [[0, 0], [0, 0]], [[.1, .1], [.1, .1]], [[.2, .2], [.2, .2]], ...
# Best will be [[.5, .5], [.5, .5]].
class DummyReconstructor(StandardIterativeReconstructor):
def _setup(self, observation):
self.setup_var = 'dummy_val'
def _compute_iterate(self, observation, reco_previous, out):
out[:] = reco_previous + 0.1
test_data = DataPairs([observation], [ground_truth])
tt = TaskTable()
r = DummyReconstructor(reco_space=domain)
hyper_param_choices = {'iterations': list(range(10))}
known_best_choice = {'iterations': 5}
path = 'dummypath'
options = {'save_best_reconstructor': {'path': path, 'measure': PSNR}}
tt.append(r,
test_data,
measures=[PSNR],
hyper_param_choices=hyper_param_choices,
options=options)
class ExtStringIO(StringIO):
def __init__(self, ext, f, *args, **kwargs):
self.ext = ext
self.f = f
super().__init__(*args, **kwargs)
self.ext[self.f] = self.getvalue()
def close(self):
self.ext[self.f] = self.getvalue()
super().close()
ext = {}
with patch('dival.reconstructors.reconstructor.open',
lambda f, *a, **kw: ExtStringIO(ext, f)):
tt.run()
self.assertIn(path + '_hyper_params.json', ext)
self.assertDictEqual(json.loads(ext[path + '_hyper_params.json']),
known_best_choice)
def test_iterations_hyper_param_choices(self):
# test 'iterations' in hyper_param_choices, because `run` has
# performance optimization for it
domain = odl.uniform_discr([0, 0], [1, 1], (1, 1))
ground_truth = domain.one()
observation = domain.one()
# reconstruct 1., iterates 0., 0.5, 0.75, 0.875, ...
class DummyReconstructor(StandardIterativeReconstructor):
def _setup(self, observation):
self.setup_var = 'dummy_val'
def _compute_iterate(self, observation, reco_previous, out):
out[:] = 0.5 * (observation + reco_previous)
test_data = DataPairs([observation], [ground_truth])
tt = TaskTable()
r = DummyReconstructor(reco_space=domain)
hyper_param_choices = {'iterations': [2, 3, 10]}
tt.append(r, test_data, hyper_param_choices=hyper_param_choices)
iters = []
r.callback = CallbackStore(iters)
results = tt.run(reuse_iterates=True)
self.assertAlmostEqual(1.,
results.results['reconstructions'][0, 1][0][0,
0],
delta=0.2)
self.assertNotAlmostEqual(1.,
results.results['reconstructions'][0,
0][0][0,
0],
delta=0.2)
self.assertEqual(len(iters), max(hyper_param_choices['iterations']))
print(results.results['misc'])
iters2 = []
r.callback = CallbackStore(iters2)
results2 = tt.run(reuse_iterates=False)
self.assertAlmostEqual(1.,
results2.results['reconstructions'][0, 1][0][0,
0],
delta=0.2)
self.assertNotAlmostEqual(1.,
results2.results['reconstructions'][0,
0][0][0,
0],
delta=0.2)
self.assertEqual(len(iters2), sum(hyper_param_choices['iterations']))
def test(self):
reco_space = odl.uniform_discr([0, 0], [1, 1], (2, 2))
observation_space = odl.uniform_discr([0, 0], [1, 1], (1, 1))
ground_truth = [reco_space.one(), reco_space.zero()]
observations = [observation_space.one(), observation_space.zero()]
data_pairs = DataPairs(observations, ground_truth)
for obs_true, gt_true, (obs, gt) in zip(observations, ground_truth,
data_pairs):
self.assertEqual(obs, obs_true)
self.assertEqual(gt, gt_true)
self.assertEqual(len(data_pairs), len(observations))
for obs_true, gt_true, (obs, gt) in zip(observations[::-1],
ground_truth[::-1],
data_pairs[::-1]):
self.assertEqual(obs, obs_true)
self.assertEqual(gt, gt_true)
def test(self):
reco_space = odl.uniform_discr(
min_pt=[-64, -64], max_pt=[64, 64], shape=[128, 128])
phantom = odl.phantom.shepp_logan(reco_space, modified=True)
geometry = odl.tomo.parallel_beam_geometry(reco_space, 30)
ray_trafo = odl.tomo.RayTransform(reco_space, geometry, impl='skimage')
proj_data = ray_trafo(phantom)
observation = np.asarray(
proj_data +
np.random.normal(loc=0., scale=2., size=proj_data.shape))
test_data = DataPairs(observation, phantom)
tt = TaskTable()
fbp_reconstructor = FBPReconstructor(ray_trafo, hyper_params={
'filter_type': 'Hann',
'frequency_scaling': 0.8})
tt.append(fbp_reconstructor, test_data, measures=[PSNR, SSIM])
tt.run()
self.assertGreater(
tt.results.results['measure_values'][0, 0]['psnr'][0], 15.)
np.random.seed(0)
# %% data
reco_space = odl.uniform_discr(min_pt=[-20, -20],
max_pt=[20, 20],
shape=[300, 300],
dtype='float32')
phantom = odl.phantom.shepp_logan(reco_space, modified=True)
ground_truth = phantom
geometry = odl.tomo.cone_beam_geometry(reco_space, 40, 40, 360)
ray_trafo = odl.tomo.RayTransform(reco_space, geometry, impl='astra_cpu')
proj_data = ray_trafo(phantom)
observation = (proj_data + np.random.poisson(0.3, proj_data.shape)).asarray()
test_data = DataPairs(observation, ground_truth, name='shepp-logan + pois')
# %% task table and reconstructors
eval_tt = TaskTable()
fbp_reconstructor = FBPReconstructor(ray_trafo,
hyper_params={
'filter_type': 'Hann',
'frequency_scaling': 0.8
})
cg_reconstructor = CGReconstructor(ray_trafo, reco_space.zero(), 4)
gn_reconstructor = GaussNewtonReconstructor(ray_trafo, reco_space.zero(), 2)
lw_reconstructor = LandweberReconstructor(ray_trafo, reco_space.zero(), 8)
mlem_reconstructor = MLEMReconstructor(ray_trafo, 0.5 * reco_space.one(), 1)
reconstructors = [
def get_data_pairs_per_index(self, part='train', index=None):
"""
Return specific samples from data part as :class:`.DataPairs` object.
Only supports datasets with two elements per sample.
For datasets not supporting random access, samples are extracted from
:meth:`generator`, which can be computationally expensive.
Parameters
----------
part : {``'train'``, ``'validation'``, ``'test'``}, optional
The data part. Default is ``'train'``.
index : int or list of int, optional
Indices of the samples in the data part. Default is ``'[0]'``.
"""
if self.get_num_elements_per_sample() != 2:
raise ValueError(
'`get_data_pairs` only supports datasets with'
'2 elements per sample, this dataset has {:d}'.format(
self.get_num_elements_per_sample()))
if index is None:
index = [0]
if not isinstance(index, list) and not isinstance(index, int):
raise ValueError('`index` must be an integer or a list of '
'integer elements')
elif isinstance(index, int):
index = [index]
name = '{} part: index{}'.format(part, index)
if len(index) == 0:
data_pairs = DataPairs([], [], name=name)
return data_pairs
if not (min(index) >= 0 and max(index) <= self.get_len(part) - 1):
raise ValueError('index out of bounds. All indices must be '
'between 0 and {} (inclusively).'.format(
self.get_len(part) - 1))
if self.supports_random_access():
observations, ground_truth = [], []
for current_index in index:
obs, gt = self.get_sample(current_index, part=part)
observations.append(obs)
ground_truth.append(gt)
else:
gen = self.generator(part=part)
observations = [None] * len(index)
ground_truth = [None] * len(index)
argsort_index = np.argsort(index)
c = 0
current_index = index[argsort_index[0]]
for i, (obs, gt) in enumerate(gen):
while i == current_index:
observations[argsort_index[c]] = obs
ground_truth[argsort_index[c]] = gt
c += 1
if c == len(index):
break
current_index = index[argsort_index[c]]
if c == len(index):
break
name = '{} part: index{}'.format(part, index)
data_pairs = DataPairs(observations, ground_truth, name=name)
return data_pairs
from dival.util.odl_utility import uniform_discr_element
from dival.data import DataPairs
from dival.evaluation import TaskTable
from dival.measure import L2
from dival import Reconstructor
import numpy as np
np.random.seed(1)
ground_truth = uniform_discr_element([0, 1, 2, 3, 4, 5, 6])
observation = ground_truth + 1
observation += np.random.normal(size=observation.shape)
test_data = DataPairs(observation, ground_truth, name='x + 1 + normal')
eval_tt = TaskTable()
class MinusOneReconstructor(Reconstructor):
def reconstruct(self, observation):
return observation - 1
reconstructor = MinusOneReconstructor(name='y-1')
eval_tt.append(reconstructor=reconstructor, test_data=test_data,
measures=[L2])
results = eval_tt.run()
results.plot_reconstruction(0)
print(results)
