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cdtools/CDTools/models/multislice_2d_ptycho.py
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Python

from __future__ import division, print_function, absolute_import
import torch as t
from CDTools.models import CDIModel
from CDTools.datasets import Ptycho2DDataset
from CDTools import tools
from CDTools.tools import cmath
from CDTools.tools import plotting as p
from matplotlib import pyplot as plt
from datetime import datetime
import numpy as np
from copy import copy
class Multislice2DPtycho(CDIModel):
def __init__(self, wavelength, detector_geometry,
probe_basis,
probe_guess, obj_guess, dz, nz,
detector_slice=None,
surface_normal=np.array([0.,0.,1.]),
min_translation = t.Tensor([0,0]),
background = None, translation_offsets=None, mask=None,
weights = None, translation_scale = 1, saturation=None,
probe_support = None, obj_support=None, oversampling=1):
super(Multislice2DPtycho,self).__init__()
self.wavelength = t.Tensor([wavelength])
self.detector_geometry = copy(detector_geometry)
self.dz = dz
self.nz = nz
det_geo = self.detector_geometry
if hasattr(det_geo, 'distance'):
det_geo['distance'] = t.Tensor(det_geo['distance'])
if hasattr(det_geo, 'basis'):
det_geo['basis'] = t.Tensor(det_geo['basis'])
if hasattr(det_geo, 'corner'):
det_geo['corner'] = t.Tensor(det_geo['corner'])
self.min_translation = t.Tensor(min_translation)
self.probe_basis = t.Tensor(probe_basis)
self.detector_slice = detector_slice
self.surface_normal = t.Tensor(surface_normal)
self.saturation = saturation
if mask is None:
self.mask = mask
else:
self.mask = t.BoolTensor(mask)
# We rescale the probe here so it learns at the same rate as the
# object
if probe_guess.dim() > 3:
self.probe_norm = 1 * t.max(tools.cmath.cabs(probe_guess[0].to(t.float32)))
else:
self.probe_norm = 1 * t.max(tools.cmath.cabs(probe_guess.to(t.float32)))
self.probe = t.nn.Parameter(probe_guess.to(t.float32)
/ self.probe_norm)
self.obj = t.nn.Parameter(obj_guess.to(t.float32))
if background is None:
if detector_slice is not None:
background = 1e-6 * t.ones(self.probe[0][self.detector_slice].shape[:-1])
else:
background = 1e-6 * t.ones(self.probe[0].shape[:-1])
self.background = t.nn.Parameter(t.Tensor(background).to(t.float32))
if weights is None:
self.weights = None
else:
self.weights = t.nn.Parameter(t.Tensor(weights).to(t.float32))
if translation_offsets is None:
self.translation_offsets = None
else:
self.translation_offsets = t.nn.Parameter(t.Tensor(translation_offsets).to(t.float32)/ translation_scale)
self.translation_scale = translation_scale
if probe_support is not None:
self.probe_support = probe_support
else:
self.probe_support = t.ones_like(self.probe[0])
if obj_support is not None:
self.obj_support = obj_support
self.obj.data = self.obj * obj_support
else:
self.obj_support = t.ones_like(self.obj)
self.oversampling = oversampling
spacing = np.linalg.norm(self.probe_basis,axis=0)
shape = np.array(self.probe.shape[1:-1])
self.as_prop = tools.propagators.generate_angular_spectrum_propagator(shape, spacing, self.wavelength, self.dz)
@classmethod
def from_dataset(cls, dataset, dz, nz, probe_size=None, randomize_ang=0, padding=0, n_modes=1, translation_scale = 1, saturation=None, probe_support_radius=None, propagation_distance=None, restrict_obj=-1, scattering_mode=None, oversampling=1, auto_center=True):
wavelength = dataset.wavelength
det_basis = dataset.detector_geometry['basis']
det_shape = dataset[0][1].shape
distance = dataset.detector_geometry['distance']
# always do this on the cpu
get_as_args = dataset.get_as_args
dataset.get_as(device='cpu')
(indices, translations), patterns = dataset[:]
dataset.get_as(*get_as_args[0],**get_as_args[1])
# Set to none to avoid issues with things outside the detector
if auto_center:
center = tools.image_processing.centroid(t.sum(patterns,dim=0))
else:
center = None
# Then, generate the probe geometry from the dataset
ewg = tools.initializers.exit_wave_geometry
probe_basis, probe_shape, det_slice = ewg(det_basis,
det_shape,
wavelength,
distance,
center=center,
padding=padding,
opt_for_fft=False,
oversampling=oversampling)
if hasattr(dataset, 'sample_info') and \
dataset.sample_info is not None and \
'orientation' in dataset.sample_info:
surface_normal = dataset.sample_info['orientation'][2]
else:
surface_normal = np.array([0.,0.,1.])
# If this information is supplied when the function is called,
# then we override the information in the .cxi file
if scattering_mode in {'t', 'transmission'}:
surface_normal = np.array([0.,0.,1.])
elif scattering_mode in {'r', 'reflection'}:
outgoing_dir = np.cross(det_basis[:,0], det_basis[:,1])
outgoing_dir /= np.linalg.norm(outgoing_dir)
surface_normal = outgoing_dir + np.array([0.,0.,1.])
surface_normal /= np.linalg.norm(outgoing_dir)
# Next generate the object geometry from the probe geometry and
# the translations
pix_translations = tools.interactions.translations_to_pixel(probe_basis, translations, surface_normal=surface_normal)
obj_size, min_translation = tools.initializers.calc_object_setup(probe_shape, pix_translations, padding=200)
if hasattr(dataset, 'background') and dataset.background is not None:
background = t.sqrt(dataset.background)
else:
background = None
# Finally, initialize the probe and object using this information
if probe_size is None:
probe = tools.initializers.SHARP_style_probe(dataset, probe_shape, det_slice, propagation_distance=propagation_distance, oversampling=oversampling)
else:
probe = tools.initializers.gaussian_probe(dataset, probe_basis, probe_shape, probe_size, propagation_distance=propagation_distance)
# Now we initialize all the subdominant probe modes
probe_max = t.max(cmath.cabs(probe))
probe_stack = [0.01 * probe_max * t.rand(probe.shape,dtype=probe.dtype) for i in range(n_modes - 1)]
probe = t.stack([probe,] + probe_stack)
obj = tools.cmath.expi(randomize_ang * (t.rand(obj_size)-0.5))
det_geo = dataset.detector_geometry
translation_offsets = 0 * (t.rand((len(dataset),2)) - 0.5)
weights = t.ones(len(dataset))
if hasattr(dataset, 'mask') and dataset.mask is not None:
mask = dataset.mask.to(t.bool)
else:
mask = None
if probe_support_radius is not None:
probe_support = t.zeros_like(probe[0].to(dtype=t.float32))
p_cent = np.array(probe.shape[1:3]).astype(int) // 2
psr = int(probe_support_radius)
probe_support[p_cent[0]-psr:p_cent[0]+psr,
p_cent[1]-psr:p_cent[1]+psr] = 1
probe = probe * probe_support[None,:,:]
else:
probe_support = None;
if restrict_obj != -1:
ro = restrict_obj
os = np.array(obj_size)
ps = np.array(probe_shape)
obj_support = t.zeros_like(obj.to(dtype=t.float32))
obj_support[ps[0]//2-ro:os[0]+ro-ps[0]//2,
ps[1]//2-ro:os[1]+ro-ps[1]//2] = 1
else:
obj_support = None
return cls(wavelength, det_geo, probe_basis, probe, obj, dz, nz,
detector_slice=det_slice,
surface_normal=surface_normal,
min_translation=min_translation,
translation_offsets = translation_offsets,
weights=weights, mask=mask, background=background,
translation_scale=translation_scale,
saturation=saturation,
probe_support=probe_support,
obj_support=obj_support,
oversampling=oversampling)
def interaction(self, index, translations):
pix_trans = tools.interactions.translations_to_pixel(self.probe_basis,
translations,
surface_normal=self.surface_normal)
pix_trans -= self.min_translation
if self.translation_offsets is not None:
pix_trans += self.translation_scale * self.translation_offsets[index]
all_exit_waves = []
for i in range(self.probe.shape[0]):
pr = self.probe[i] * self.probe_support
#exit_waves = pr
#print(self.probe_norm)
#for i in range(self.nz):
exit_waves = []
if len(pix_trans.shape) == 1:
pix_trans = [pix_trans]
for trans in pix_trans:
exit_wave = self.probe_norm * pr
for i in range(self.nz-1):
#exit_wave = tools.interactions.ptycho_2D_sinc(exit_wave,
# self.obj_support * self.obj,
# trans,
# shift_probe=True)
exit_wave = tools.interactions.ptycho_2D_round(exit_wave,
self.obj_support * cmath.cexpi(self.obj.data/self.nz),
trans)
exit_wave = tools.propagators.near_field(exit_wave,self.as_prop)
#tools.plotting.plot_amplitude(exit_wave)
#plt.show()
# only final layer gets a derivative
exit_wave = tools.interactions.ptycho_2D_round(exit_wave,
self.obj_support * cmath.cexpi(0.1*self.obj),
trans)
exit_waves.append(exit_wave)
exit_waves = t.stack(exit_waves)
if np.array(index).size == 1:
index = [index]
strip_first_index = True
else:
strip_first_index = False
if exit_waves.dim() == 4:
exit_waves = self.weights[index][:,None,None,None] * exit_waves
else:
exit_waves = self.weights[index] * exit_waves
if strip_first_index:
exit_waves = exit_waves[0,...]
all_exit_waves.append(exit_waves)
return t.stack(all_exit_waves)
def forward_propagator(self, wavefields):
return tools.propagators.far_field(wavefields)
def backward_propagator(self, wavefields):
return tools.propagators.inverse_far_field(wavefields)
def measurement(self, wavefields):
return tools.measurements.quadratic_background(wavefields,
self.background,
detector_slice=self.detector_slice,
measurement=tools.measurements.incoherent_sum,
saturation=self.saturation,
oversampling=self.oversampling)
def loss(self, sim_data, real_data, mask=None):
regularizer = t.mean(t.abs(self.obj))
loss = tools.losses.amplitude_mse(real_data, sim_data, mask=mask)
lambd = 1
return loss + lambd * regularizer
#return tools.losses.poisson_nll(real_data, sim_data, mask=mask)
def to(self, *args, **kwargs):
super(Multislice2DPtycho, self).to(*args, **kwargs)
self.wavelength = self.wavelength.to(*args,**kwargs)
# move the detector geometry too
det_geo = self.detector_geometry
if hasattr(det_geo, 'distance'):
det_geo['distance'] = det_geo['distance'].to(*args,**kwargs)
if hasattr(det_geo, 'basis'):
det_geo['basis'] = det_geo['basis'].to(*args,**kwargs)
if hasattr(det_geo, 'corner'):
det_geo['corner'] = det_geo['corner'].to(*args,**kwargs)
if self.mask is not None:
self.mask = self.mask.to(*args, **kwargs)
self.min_translation = self.min_translation.to(*args,**kwargs)
self.probe_basis = self.probe_basis.to(*args,**kwargs)
self.probe_norm = self.probe_norm.to(*args,**kwargs)
self.probe_support = self.probe_support.to(*args,**kwargs)
self.obj_support = self.obj_support.to(*args,**kwargs)
self.surface_normal = self.surface_normal.to(*args, **kwargs)
self.as_prop = self.as_prop.to(*args, **kwargs)
def sim_to_dataset(self, args_list):
# In the future, potentially add more control
# over what metadata is saved (names, etc.)
# First, I need to gather all the relevant data
# that needs to be added to the dataset
entry_info = {'program_name': 'CDTools',
'instrument_n': 'Simulated Data',
'start_time': datetime.now()}
surface_normal = self.surface_normal.detach().cpu().numpy()
xsurfacevec = np.cross(np.array([0.,1.,0.]), surface_normal)
xsurfacevec /= np.linalg.norm(xsurfacevec)
ysurfacevec = np.cross(surface_normal, xsurfacevec)
ysurfacevec /= np.linalg.norm(ysurfacevec)
orientation = np.array([xsurfacevec, ysurfacevec, surface_normal])
sample_info = {'description': 'A simulated sample',
'orientation': orientation}
detector_geometry = self.detector_geometry
mask = self.mask
wavelength = self.wavelength
indices, translations = args_list
# Then we simulate the results
data = self.forward(indices, translations)
# And finally, we make the dataset
return Ptycho2DDataset(translations, data,
entry_info = entry_info,
sample_info = sample_info,
wavelength=wavelength,
detector_geometry=detector_geometry,
mask=mask)
def corrected_translations(self,dataset):
translations = dataset.translations.to(dtype=self.probe.dtype,device=self.probe.device)
t_offset = tools.interactions.pixel_to_translations(self.probe_basis,self.translation_offsets*self.translation_scale,surface_normal=self.surface_normal)
return translations + t_offset
# Needs to be updated to allow for plotting to an existing figure
plot_list = [
('Dominant Probe Amplitude',
lambda self, fig: p.plot_amplitude(self.probe[0], fig=fig, basis=self.probe_basis)),
('Dominant Probe Phase',
lambda self, fig: p.plot_phase(self.probe[0], fig=fig, basis=self.probe_basis)),
('Subdominant Probe Amplitude',
lambda self, fig: p.plot_amplitude(self.probe[1], fig=fig, basis=self.probe_basis),
lambda self: len(self.probe) >=2),
('Subdominant Probe Phase',
lambda self, fig: p.plot_phase(self.probe[1], fig=fig, basis=self.probe_basis),
lambda self: len(self.probe) >=2),
('Object Amplitude',
lambda self, fig: p.plot_amplitude(self.obj, fig=fig, basis=self.probe_basis)),
('Object Phase',
lambda self, fig: p.plot_phase(self.obj, fig=fig, basis=self.probe_basis)),
('Corrected Translations',
lambda self, fig, dataset: p.plot_translations(self.corrected_translations(dataset), fig=fig)),
('Background',
lambda self, fig: plt.figure(fig.number) and plt.imshow(self.background.detach().cpu().numpy()**2))
]
def save_results(self, dataset):
basis = self.probe_basis.detach().cpu().numpy()
translations = self.corrected_translations(dataset).detach().cpu().numpy()
probe = cmath.torch_to_complex(self.probe.detach().cpu())
probe = probe * self.probe_norm.detach().cpu().numpy()
obj = cmath.torch_to_complex(self.obj.detach().cpu())
background = self.background.detach().cpu().numpy()**2
weights = self.weights.detach().cpu().numpy()
dz = self.dz
nz = self.nz
prop = self.as_prop
return {'basis':basis, 'translation':translations,
'probe':probe,'obj':obj,
'background':background,
'weights':weights, 'dz':dz, 'nz':nz,
'interlayer propagator': prop}