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cdtools/CDTools/models/fancy_ptycho.py
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Python

import torch as t
from CDTools.models import CDIModel
from CDTools.datasets import Ptycho2DDataset
from CDTools import tools
from CDTools.tools import plotting as p
from CDTools.tools import analysis
from matplotlib import pyplot as plt
from datetime import datetime
import numpy as np
from scipy import linalg as sla
from copy import copy
__all__ = ['FancyPtycho']
class FancyPtycho(CDIModel):
def __init__(self, wavelength, detector_geometry,
probe_basis,
probe_guess, obj_guess,
detector_slice=None,
surface_normal=t.tensor([0., 0., 1.], dtype=t.float32),
min_translation=t.tensor([0, 0], dtype=t.float32),
background=None, translation_offsets=None, mask=None,
weights=None, translation_scale=1, saturation=None,
probe_support=None, oversampling=1,
loss='amplitude mse', units='um'):
super(FancyPtycho, self).__init__()
self.wavelength = t.tensor(wavelength)
self.detector_geometry = copy(detector_geometry)
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 = copy(detector_slice)
self.surface_normal = t.tensor(surface_normal)
self.saturation = saturation
self.units = units
if mask is None:
self.mask = mask
else:
self.mask = t.tensor(mask, dtype=t.bool)
probe_guess = t.tensor(probe_guess, dtype=t.complex64)
obj_guess = t.tensor(obj_guess, dtype=t.complex64)
# We rescale the probe here so it learns at the same rate as the
# object
if probe_guess.dim() > 2:
self.probe_norm = 1 * t.max(t.abs(probe_guess[0]))
else:
self.probe_norm = 1 * t.max(t.abs(probe_guess))
self.probe = t.nn.Parameter(probe_guess / self.probe_norm)
self.obj = t.nn.Parameter(obj_guess)
if background is None:
if detector_slice is not None:
background = 1e-6 * t.ones(
self.probe[0][self.detector_slice].shape,
dtype=t.float32)
else:
background = 1e-6 * t.ones(self.probe[0].shape,
dtype=t.float32)
self.background = t.nn.Parameter(background)
if weights is None:
self.weights = None
else:
# We now need to distinguish between real-valued per-image
# weights and complex-valued per-mode weight matrices
if len(weights.shape) == 1:
# This is if it's just a list of numbers
self.weights = t.nn.Parameter(t.tensor(weights,
dtype=t.float32))
else:
# Now this is a matrix of weights, so it needs to be complex
self.weights = t.nn.Parameter(t.tensor(weights,
dtype=t.complex64))
if translation_offsets is None:
self.translation_offsets = None
else:
t_o = t.tensor(translation_offsets, dtype=t.float32)
t_o = t_o / translation_scale
self.translation_offsets = t.nn.Parameter(t_o)
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], dtype=t.bool)
self.oversampling = oversampling
# Here we set the appropriate loss function
if (loss.lower().strip() == 'amplitude mse'
or loss.lower().strip() == 'amplitude_mse'):
self.loss = tools.losses.amplitude_mse
elif (loss.lower().strip() == 'poisson nll'
or loss.lower().strip() == 'poisson_nll'):
self.loss = tools.losses.poisson_nll
else:
raise KeyError('Specified loss function not supported')
@classmethod
def from_dataset(cls, dataset, probe_size=None, randomize_ang=0, padding=0, n_modes=1, dm_rank=None, translation_scale=1, saturation=None, probe_support_radius=None, propagation_distance=None, scattering_mode=None, oversampling=1, auto_center=False, opt_for_fft=False, loss='amplitude mse', units='um'):
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')
# We include the *extras to make this work even with datasets, like
# polarization dependent datasets, that might toss out extra inputs
(indices, translations, *extras), 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=opt_for_fft,
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(surface_normal)
# 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(t.abs(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)
# probe = t.stack([tools.propagators.far_field(probe),] + probe_stack)
obj = t.exp(1j * randomize_ang * (t.rand(obj_size)-0.5))
det_geo = dataset.detector_geometry
translation_offsets = 0 * (t.rand((len(dataset), 2)) - 0.5)
if dm_rank is not None and dm_rank != 0:
if dm_rank > n_modes:
raise KeyError('Density matrix rank cannot be greater than the number of modes. Use dm_rank = -1 to use a full rank matrix.')
elif dm_rank == -1:
# dm_rank == -1 is defined to mean full-rank
dm_rank = n_modes
Ws = t.zeros(len(dataset), dm_rank, n_modes, dtype=t.complex64)
# Start with as close to the identity matrix as possible,
# cutting of when we hit the specified maximum rank
for i in range(0, dm_rank):
Ws[:, i, i] = 1
else:
# dm_rank == None or dm_rank = 0 triggers a special case where
# a standard incoherent multi-mode model is used. This is the
# default, because it is so common.
# In this case, we define a set of weights which only has one index
Ws = 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(probe[0].shape, dtype=t.bool)
xs, ys = np.mgrid[:probe.shape[-2], :probe.shape[-1]]
xs = xs - np.mean(xs)
ys = ys - np.mean(ys)
Rs = np.sqrt(xs**2 + ys**2)
probe_support[Rs < probe_support_radius] = 1
probe = probe * probe_support[None, :, :]
else:
probe_support = None
return cls(wavelength, det_geo, probe_basis, probe, obj,
detector_slice=det_slice,
surface_normal=surface_normal,
min_translation=min_translation,
translation_offsets=translation_offsets,
weights=Ws, mask=mask, background=background,
translation_scale=translation_scale,
saturation=saturation,
probe_support=probe_support,
oversampling=oversampling,
loss=loss, units=units)
def interaction(self, index, translations, *args):
# The *args is included so that this can work even when given, say,
# a polarized ptycho dataset that might spit out more inputs.
# Step 1 is to convert the translations for each position into a
# value in pixels
pix_trans = tools.interactions.translations_to_pixel(
self.probe_basis,
translations,
surface_normal=self.surface_normal)
pix_trans -= self.min_translation
# We then add on any recovered translation offset, if they exist
if self.translation_offsets is not None:
pix_trans += (self.translation_scale *
self.translation_offsets[index])
# This restricts the basis probes to stay within the probe support
basis_prs = self.probe * self.probe_support[..., :, :]
# Now we construct the probes for each shot from the basis probes
Ws = self.weights[index]
if len(self.weights[0].shape) == 0:
# If a purely stable coherent illumination is defined
prs = Ws[..., None, None, None] * basis_prs
else:
# If a frame-by-frame weight matrix is defined
# This takes the dot product of all the weight matrices with
# the probes. The output has dimensions of translation, then
# coherent mode index, then x,y, and then complex index
# Maybe this can be done with a matmul now?
prs = t.sum(Ws[..., None, None] * basis_prs, axis=-3)
# Now we actually do the interaction, using the sinc subpixel
# translation model as per usual
exit_waves = self.probe_norm * tools.interactions.ptycho_2D_sinc(
prs, self.obj, pix_trans,
shift_probe=True, multiple_modes=True)
return 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)
# Note: No "loss" function is defined here, because it is added
# dynamically during object creation in __init__
def to(self, *args, **kwargs):
super(FancyPtycho, 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.surface_normal = self.surface_normal.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=t.float32, device=self.probe.device)
if (hasattr(self, 'translation_offsets') and
self.translation_offsets is not None):
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
else:
return translations
def get_rhos(self):
# If this is the general unified mode model
if self.weights.dim() >= 2:
Ws = self.weights.detach().cpu().numpy()
rhos_out = np.matmul(np.swapaxes(Ws, 1, 2), Ws.conj())
return rhos_out
# This is the purely incoherent case
else:
return np.array([np.eye(self.probe.shape[0])]*self.weights.shape[0],
dtype=np.complex64)
def tidy_probes(self, normalization=1, normalize=False):
"""Tidies up the probes
What we want to do here is use all the information on all the probes
to calculate a natural basis for the experiment, and update all the
density matrices to operate in that updated basis
"""
# First we treat the purely incoherent case
# I don't love this pattern of using an if statement with a return
# to catch this case, but because it's so much simpler than the
# unified mode case I think it's appropriate
if self.weights.dim() == 1:
probe = self.probe.detach().cpu().numpy()
ortho_probes = analysis.orthogonalize_probes(probe)
self.probe.data = t.as_tensor(
ortho_probes,
device=self.probe.device,
dtype=self.probe.dtype)
return
# This is for the unified mode case
# Note to future: We could probably do this more cleanly with an
# SVD directly on the Ws matrix, instead of an eigendecomposition
# of the rho matrix.
rhos = self.get_rhos()
overall_rho = np.mean(rhos, axis=0)
probe = self.probe.detach().cpu().numpy()
ortho_probes, A = analysis.orthogonalize_probes(
probe, density_matrix=overall_rho,
keep_transform=True, normalize=normalize)
Aconj = A.conj()
Atrans = np.transpose(A)
new_rhos = np.matmul(Atrans, np.matmul(rhos, Aconj))
new_rhos /= normalization
ortho_probes *= np.sqrt(normalization)
dm_rank = self.weights.shape[1]
new_Ws = []
for rho in new_rhos:
# These are returned from smallest to largest - we want to keep
# the largest ones
w, v = sla.eigh(rho)
w = w[::-1][:dm_rank]
v = v[:, ::-1][:, :dm_rank]
# For situations where the rank of the density matrix is not
# full in reality, but we keep more modes around than needed,
# some ws can go negative due to numerical error! This is
# extremely rare, but comon enough to cause crashes occasionally
# when there are thousands of individual matrices to transform
# every time this is called.
w = np.maximum(w, 0)
new_Ws.append(np.dot(np.diag(np.sqrt(w)), v.transpose()))
new_Ws = np.array(new_Ws)
self.weights.data = t.as_tensor(
new_Ws, dtype=self.weights.dtype, device=self.weights.device)
self.probe.data = t.as_tensor(
ortho_probes, device=self.probe.device, dtype=self.probe.dtype)
def plot_wavefront_variation(self, dataset, fig=None, mode='amplitude', **kwargs):
def get_probes(idx):
basis_prs = self.probe * self.probe_support[..., :, :]
prs = t.sum(self.weights[idx, :, :, None, None] * basis_prs,
axis=-4)
ortho_probes = analysis.orthogonalize_probes(prs)
if mode.lower() == 'amplitude':
return np.abs(ortho_probes.detach().cpu().numpy())
if mode.lower() == 'root_sum_intensity':
return np.sum(np.abs(ortho_probes.detach().cpu().numpy())**2,
axis=0)
if mode.lower() == 'phase':
return np.angle(ortho_probes.detach().cpu().numpy())
probe_matrix = np.zeros([self.probe.shape[0]]*2,
dtype=np.complex64)
np_probes = self.probe.detach().cpu().numpy()
for i in range(probe_matrix.shape[0]):
for j in range(probe_matrix.shape[0]):
probe_matrix[i,j] = np.sum(np_probes[i]*np_probes[j].conj())
weights = self.weights.detach().cpu().numpy()
probe_intensities = np.sum(np.tensordot(weights, probe_matrix, axes=1)
* weights.conj(), axis=2)
# Imaginary part is already essentially zero up to rounding error
probe_intensities = np.real(probe_intensities)
values = np.sum(probe_intensities, axis=1)
if mode.lower() == 'amplitude' or mode.lower() == 'root_sum_intensity':
cmap = 'viridis'
else:
cmap = 'twilight'
p.plot_nanomap_with_images(self.corrected_translations(dataset), get_probes, values=values, fig=fig, units=self.units, basis=self.probe_basis, nanomap_colorbar_title='Total Probe Intensity', cmap=cmap, **kwargs),
plot_list = [
('',
lambda self, fig, dataset: self.plot_wavefront_variation(dataset, fig=fig, mode='root_sum_intensity', image_title='Root Summed Probe Intensities', image_colorbar_title='Square Root of Intensity'),
lambda self: len(self.weights.shape) >= 2),
('',
lambda self, fig, dataset: self.plot_wavefront_variation(dataset, fig=fig, mode='amplitude', image_title='Probe Amplitudes (scroll to view modes)', image_colorbar_title='Probe Amplitude'),
lambda self: len(self.weights.shape) >= 2),
('',
lambda self, fig, dataset: self.plot_wavefront_variation(dataset, fig=fig, mode='phase', image_title='Probe Phases (scroll to view modes)', image_colorbar_title='Probe Phase'),
lambda self: len(self.weights.shape) >= 2),
('Basis Probe Amplitudes (scroll to view modes)',
lambda self, fig: p.plot_amplitude(self.probe, fig=fig, basis=self.probe_basis, units=self.units)),
('Basis Probe Phases (scroll to view modes)',
lambda self, fig: p.plot_phase(self.probe, fig=fig, basis=self.probe_basis, units=self.units)),
('Average Density Matrix Amplitudes',
lambda self, fig: p.plot_amplitude(np.nanmean(np.abs(self.get_rhos()), axis=0), fig=fig),
lambda self: len(self.weights.shape) >= 2),
('% Power in Top Mode (only accurate after tidy_probes)',
lambda self, fig, dataset: p.plot_nanomap(self.corrected_translations(dataset), analysis.calc_top_mode_fraction(self.get_rhos()), fig=fig, units=self.units),
lambda self: len(self.weights.shape) >= 2),
('Object Amplitude',
lambda self, fig: p.plot_amplitude(self.obj, fig=fig, basis=self.probe_basis, units=self.units)),
('Object Phase',
lambda self, fig: p.plot_phase(self.obj, fig=fig, basis=self.probe_basis, units=self.units)),
('Corrected Translations',
lambda self, fig, dataset: p.plot_translations(self.corrected_translations(dataset), fig=fig, units=self.units)),
('Background',
lambda self, fig: plt.figure(fig.number) and plt.imshow(self.background.detach().cpu().numpy()**2))
]
# def plot_errors(self, dataset):
def save_results(self, dataset):
basis = self.probe_basis.detach().cpu().numpy()
translations = self.corrected_translations(dataset).detach().cpu().numpy()
probe = self.probe.detach().cpu().numpy()
probe = probe * self.probe_norm.detach().cpu().numpy()
obj = self.obj.detach().cpu().numpy()
background = self.background.detach().cpu().numpy()**2
weights = self.weights.detach().cpu().numpy()
return {'basis': basis, 'translation': translations,
'probe': probe, 'obj': obj,
'background': background,
'weights': weights}