Files
cdtools/examples/near_field_ptycho.py
T

56 lines
1.7 KiB
Python

import cdtools
import torch as t
from matplotlib import pyplot as plt
filename = 'example_data/PETRAIII_P25_Near_Field_Ptycho.cxi'
dataset = cdtools.datasets.Ptycho2DDataset.from_cxi(filename)
dataset.inspect()
# Setting near_field equal to True uses an angular spectrum propagator in
# lieu of the default Fourier-transform propagator for far-field ptychography.
#
# If propagation_distance is not set, it assumes that the geometry is
# a standard near-field geometry with flat illumination wavefronts, and
# pulls the sample to detector distance from dataset.distance
#
# If propagation_distance is set, it assumes a Fresnel scaling theorem
# geometry with:
#
# - distance (from the dataset): The sample-to-detector distance
# - propagation_distance: The focus-to-sample distance
#
model = cdtools.models.FancyPtycho.from_dataset(
dataset,
n_modes=1,
near_field=True,
propagation_distance=3.65e-3, # 3.65 downstream from focus
units='um', # Set the units for the live plots
obj_view_crop=-35, # Expand the view for the live plots
loss="poisson_nll", # Best option for photon-counting detectors
panel_plot_mode=True, # Set to False to get individual figures
)
if t.cuda.is_available():
model.to(device='cuda')
dataset.get_as(device='cuda')
model.inspect(dataset)
recon = cdtools.reconstructors.AdamReconstructor(model, dataset)
for loss in recon.optimize(100, lr=0.04, batch_size=10):
print(model.report())
model.inspect(dataset, min_interval=5)
for loss in recon.optimize(50, lr=0.005, batch_size=50):
print(model.report())
model.inspect(dataset, min_interval=5)
# This orthogonalizes the recovered probe modes
model.tidy_probes()
model.inspect(dataset, replot_all=True)
model.compare(dataset)
plt.show()