Files
cdtools/CDTools/models/__init__.py
T

474 lines
17 KiB
Python

"""This module contains all the models for different CDI Reconstructions
All the reconstructions are coordinated through the ptychography models
defined here. The models are, at their core, just subclasses of the
:code:`torch.nn.model` class, so they contain the same structure of
parameters, etc. Their central functionality is as a simulation that maps
some input (usually, the index number of a scan point) to an output that
corresponds to the measured data (usually, a diffraction pattern). This
model can then be used as the heart of an automatic differentiation
reconstruction which retrieves the parameters that were used in the model.
The subclasses of the main CDIModel class are required to define their
own implementations of the following functions:
Loading and Saving
------------------
from_dataset
Creates a CDIModel from an appropriate CDataset
simulate_to_dataset
Creates a CDataset from the simulation defined in the model
save_results
Saves out a dictionary with the recovered parameters
Simulation
----------
interaction
Simulates exit waves from experimental parameters
forward_propagator
The propagator from the experiment plane to the detector plane
backward_propagator
Optional, the propagator from the detector plane to the experiment plane
measurement
Simulates the detector readout from a detector plane wavefront
loss
the loss function to report and use for automatic differentiation
Example implementations of all these functions can be found in the code
for the SimplePtycho class.
In addition, it is recommended to read through the tutorial section on
defining a new ptychography model before attempting to do so
"""
from __future__ import division, print_function, absolute_import
import torch as t
from torch.utils import data as torchdata
from matplotlib import pyplot as plt
from matplotlib.widgets import Slider
from matplotlib import ticker
import numpy as np
__all__ = ['CDIModel', 'SimplePtycho', 'FancyPtycho', 'Bragg2DPtycho']
class CDIModel(t.nn.Module):
"""This base model defines all the functions that must be exposed for a valid CDIModel subclass
Most of the functions only raise a NotImplementedError at this level and
must be explicitly defined by any subclass - these are noted explocitly
in the module-level intro. The work of defining the various subclasses
boils down to creating an appropriate implementation for this set of
functions.
"""
def from_dataset(self, dataset):
raise NotImplementedError()
def interaction(self, *args):
raise NotImplementedError()
def forward_propagator(self, exit_wave):
raise NotImplementedError()
def backward_propagator(self, detector_wave):
raise NotImplementedError()
def measurement(self, detector_wave):
raise NotImplementedError()
def forward(self, *args):
"""The complete forward model
This model relies on composing the interaction, forward propagator,
and measurement functions which are required to be defined by all
subclasses. It therefore should not be redefined by the subclasses.
The arguments to this function, for any given subclass, will be
the same as the arguments to the interaction function.
"""
return self.measurement(self.forward_propagator(self.interaction(*args)))
def loss(self, sim_data, real_data):
raise NotImplementedError()
def to(self, *args, **kwargs):
super(CDIModel,self).to(*args,**kwargs)
def simulate_to_dataset(self, args_list):
raise NotImplementedError()
def save_results(self):
raise NotImplementedError()
def AD_optimize(self, iterations, data_loader, optimizer, scheduler=None):
"""Runs a round of reconstruction using the provided optimizer
This is the basic automatic differentiation reconstruction tool
which all the other, algorithm-specific tools, use.
Like all the other optimization routines, it is defined as a
generator function which yields the average loss each epoch.
Parameters
----------
iterations : int
How many epochs of the algorithm to run
dataset : CDataset
The dataset to reconstruct against
optimizer : torch.optim.Optimizer
The optimizer to run the reconstruction with
scheduler : torch.optim.lr_scheduler._LRScheduler
Optional, a learning rate scheduler to use
"""
# First, calculate the normalization
normalization = 0
for inputs, patterns in data_loader:
normalization += t.sum(patterns).cpu().numpy()
for it in range(iterations):
loss = 0
N = 0
for inputs, patterns in data_loader:
N += 1
def closure():
optimizer.zero_grad()
sim_patterns = self.forward(*inputs)
if hasattr(self, 'mask'):
loss = self.loss(patterns,sim_patterns, mask=self.mask)
else:
loss = self.loss(patterns,sim_patterns)
loss.backward()
return loss
loss += optimizer.step(closure).detach().cpu().numpy()
loss /= normalization
if scheduler is not None:
scheduler.step(loss)
yield loss
def Adam_optimize(self, iterations, dataset, batch_size=15, lr=0.005, schedule=False, amsgrad=False):
"""Runs a round of reconstruction using the Adam optimizer
This is generally accepted to be the most robust algorithm for use
with ptychography. Like all the other optimization routines,
it is defined as a generator function, which yields the average
loss each epoch.
Parameters
----------
iterations : int
How many epochs of the algorithm to run
dataset : CDataset
The dataset to reconstruct against
batch_size : int
Optional, the size of the minibatches to use
lr : float
Optional, The learning rate (alpha) to use
schedule : float
Optional, whether to use the ReduceLROnPlateau scheduler
"""
# Make a dataloader
data_loader = torchdata.DataLoader(dataset, batch_size=batch_size,
shuffle=True)
# Define the optimizer
optimizer = t.optim.Adam(self.parameters(), lr = lr, amsgrad=amsgrad)
# Define the scheduler
if schedule:
scheduler = t.optim.lr_scheduler.ReduceLROnPlateau(optimizer, factor=0.2,threshold=1e-9)
else:
scheduler = None
return self.AD_optimize(iterations, data_loader, optimizer, scheduler=scheduler)
def LBFGS_optimize(self, iterations, dataset, batch_size=None,
lr=0.1,history_size=2):
"""Runs a round of reconstruction using the L-BFGS optimizer
This algorithm is often less stable that Adam, however in certain
situations or geometries it can be shockingly efficient. Like all
the other optimization routines, it is defined as a generator
function which yields the average loss each epoch.
Parameters
----------
iterations : int
How many epochs of the algorithm to run
dataset : CDataset
The dataset to reconstruct against
batch_size : int
Optional, the size of the minibatches to use
lr : float
Optional, the learning rate to use
history_size : int
Optional, the length of the history to use.
"""
# Make a dataloader
if batch_size is not None:
data_loader = torchdata.DataLoader(dataset, batch_size=batch_size,
shuffle=True)
else:
data_loader = torchdata.DataLoader(dataset)
# Define the optimizer
optimizer = t.optim.LBFGS(self.parameters(),
lr = lr, history_size=history_size)
return self.AD_optimize(iterations, data_loader, optimizer)
def SGD_optimize(self, iterations, dataset, batch_size=None,
lr=0.01, momentum=0, dampening=0, weight_decay=0,
nesterov=False):
"""Runs a round of reconstruction using the SGDoptimizer
This algorithm is often less stable that Adam, but it is simpler
and is the basic workhorse of gradience descent.
Parameters
----------
iterations : int
How many epochs of the algorithm to run
dataset : CDataset
The dataset to reconstruct against
batch_size : int
Optional, the size of the minibatches to use
lr : float
Optional, the learning rate to use
momentum : float
Optional, the length of the history to use.
"""
# Make a dataloader
if batch_size is not None:
data_loader = torchdata.DataLoader(dataset, batch_size=batch_size,
shuffle=True)
else:
data_loader = torchdata.DataLoader(dataset)
# Define the optimizer
optimizer = t.optim.SGD(self.parameters(),
lr = lr, momentum=momentum,
dampening=dampening,
weight_decay=weight_decay,
nesterov=nesterov)
return self.AD_optimize(iterations, data_loader, optimizer)
# By default, the plot_list is empty
plot_list = []
def inspect(self, dataset=None, update=True):
"""Plots all the plots defined in the model's plot_list attribute
If update is set to True, it will update any previously plotted set
of plots, if one exists, and then redraw them. Otherwise, it will
plot a new set, and any subsequent updates will update the new set
Optionally, a dataset can be passed, which then will plot any
registered plots which need to incorporate some information from
the dataset (such as geometry or a comparison with measured data).
Plots can be registered in any subclass by defining the plot_list
attribute. This should be a list of tuples in the following format:
( 'Plot Title', function_to_generate_plot(self),
function_to_determine_whether_to_plot(self))
Where the third element in the tuple (a function that returns
True if the plot is relevant) is not required.
Parameters
----------
dataset : CDataset
Optional, a dataset matched to the model type
update : bool
Whether to update existing plots or plot new ones
"""
first_update = False
if update and hasattr(self, 'figs') and self.figs:
figs = self.figs
elif update:
figs = None
self.figs = []
first_update = True
else:
figs = None
self.figs = []
idx = 0
for plots in self.plot_list:
# If a conditional is included in the plot
try:
if len(plots) >=3 and not plots[2](self):
continue
except TypeError as e:
if len(plots) >= 3 and not plots[2](self, dataset):
continue
name = plots[0]
plotter = plots[1]
if figs is None:
fig = plt.figure()
self.figs.append(fig)
else:
fig = figs[idx]
try:
plotter(self,fig)
plt.title(name)
except TypeError as e:
if dataset is not None:
try:
plotter(self, fig, dataset)
plt.title(name)
except (IndexError, KeyError, AttributeError) as e:
pass
except (IndexError, KeyError, AttributeError) as e:
pass
idx += 1
if update:
plt.draw()
fig.canvas.start_event_loop(0.001)
if first_update:
plt.pause(0.05 * len(self.figs))
def compare(self, dataset):
"""Opens a tool for comparing simulated and measured diffraction patterns
Parameters
----------
dataset : CDataset
A dataset containing the simulated diffraction patterns to compare against
"""
fig, axes = plt.subplots(1,3,figsize=(12,5.3))
fig.tight_layout(rect=[0.02, 0.09, 0.98, 0.96])
axslider = plt.axes([0.15,0.06,0.75,0.03])
def update_colorbar(im):
# If the update brought the colorbar out of whack
# (say, from clicking back in the navbar)
# Holy fuck this was annoying. Sorry future for how
# crappy this solution is.
#if not np.allclose(im.colorbar.ax.get_xlim(),
# (np.min(im.get_array()),
# np.max(im.get_array()))):
if hasattr(im, 'norecurse') and im.norecurse:
im.norecurse=False
return
im.norecurse=True
im.colorbar.set_clim(vmin=np.min(im.get_array()),vmax=np.max(im.get_array()))
im.colorbar.ax.set_ylim(0,1)
im.colorbar.set_ticks(ticker.LinearLocator(numticks=5))
im.colorbar.draw_all()
def update(idx):
idx = int(idx) % len(dataset)
fig.pattern_idx = idx
updating = True if len(axes[0].images) >= 1 else False
inputs, output = dataset[idx]
sim_data = self.forward(*inputs).detach().cpu().numpy()
sim_data = sim_data
meas_data = output.detach().cpu().numpy()
if hasattr(self, 'mask') and self.mask is not None:
mask = self.mask.detach().cpu().numpy()
else:
mask = 1
if not updating:
axes[0].set_title('Simulated')
axes[1].set_title('Measured')
axes[2].set_title('Difference')
sim = axes[0].imshow(sim_data)
meas = axes[1].imshow(meas_data * mask)
diff = axes[2].imshow((sim_data-meas_data) * mask)
cb1 = plt.colorbar(sim, ax=axes[0], orientation='horizontal',format='%.2e',ticks=ticker.LinearLocator(numticks=5),pad=0.1,fraction=0.1)
cb1.ax.tick_params(labelrotation=20)
cb1.ax.callbacks.connect('xlim_changed', lambda ax: update_colorbar(sim))
cb2 = plt.colorbar(meas, ax=axes[1], orientation='horizontal',format='%.2e',ticks=ticker.LinearLocator(numticks=5),pad=0.1,fraction=0.1)
cb2.ax.tick_params(labelrotation=20)
cb2.ax.callbacks.connect('xlim_changed', lambda ax: update_colorbar(meas))
cb3 = plt.colorbar(diff, ax=axes[2], orientation='horizontal',format='%.2e',ticks=ticker.LinearLocator(numticks=5),pad=0.1,fraction=0.1)
cb3.ax.tick_params(labelrotation=20)
cb3.ax.callbacks.connect('xlim_changed', lambda ax: update_colorbar(diff))
else:
sim = axes[0].images[-1]
sim.set_data(sim_data)
update_colorbar(sim)
meas = axes[1].images[-1]
meas.set_data(meas_data * mask)
update_colorbar(meas)
diff = axes[2].images[-1]
diff.set_data((sim_data-meas_data) * mask)
update_colorbar(diff)
# This is dumb but the slider doesn't work unless a reference to it is
# kept somewhere...
self.slider = Slider(axslider, 'Pattern #', 0, len(dataset)-1, valstep=1, valfmt="%d")
self.slider.on_changed(update)
def on_action(event):
if not hasattr(event, 'button'):
event.button = None
if not hasattr(event, 'key'):
event.key = None
if event.key == 'up' or event.button == 'up':
update(fig.pattern_idx - 1)
elif event.key == 'down' or event.button == 'down':
update(fig.pattern_idx + 1)
self.slider.set_val(fig.pattern_idx)
plt.draw()
fig.canvas.mpl_connect('key_press_event',on_action)
fig.canvas.mpl_connect('scroll_event',on_action)
update(0)
from CDTools.models.simple_ptycho import SimplePtycho
from CDTools.models.fancy_ptycho import FancyPtycho
from CDTools.models.pinhole_plane_ptycho import PinholePlanePtycho
from CDTools.models.bragg_2d_ptycho import Bragg2DPtycho