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cdtools/CDTools/datasets/polarized_ptycho_2d_dataset.py
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Python

import numpy as np
import torch as t
import h5py
import pathlib
from CDTools.datasets import Ptycho2DDataset
from CDTools.tools import data as cdtdata
from CDTools.tools import plotting
__all__ = ['PolarizedPtycho2DDataset']
class PolarizedPtycho2DDataset(Ptycho2DDataset):
"""The standard dataset for a 2D ptychography scan
Subclasses datasets.Ptycho2DDataset
This class loads and saves 2D ptychography scan data from .cxi files.
It should save and load files compatible with most reconstruction
programs, although it is only tested against SHARP.
"""
def __init__(self, translations, polarizer_angles, analyzer_angles, patterns, axes=None, *args, **kwargs):
"""The __init__ function allows construction from python objects.
The detector_geometry dictionary is defined to have the
entries defined by the outputs of data.get_detector_geometry.
Parameters
----------
translations : array (nx3 t.tensor when polarized=True)
An nx3 array containing the probe translations at each scan point
patterns : array
An nxmxl array containing the full stack of measured diffraction patterns
axes : list(str)
A
of names for the axes of the probe translations
entry_info : dict
A dictionary containing the entry_info metadata
sample_info : dict
A dictionary containing the sample_info metadata
wavelength : float
The wavelength of light used in the experiment
detector_geometry : dict
A dictionary containing the various detector geometry
parameters
mask : array
A mask for the detector, defined as 1 for live pixels, 0
for dead
background : array
An initial guess for the not-previously-subtracted
detector background
"""
super(PolarizedPtycho2DDataset,self).__init__(translations, patterns,
*args, **kwargs)
self.polarizer = t.tensor(polarizer_angles, dtype=t.float32)
self.analyzer = t.tensor(analyzer_angles, dtype=t.float32)
def _load(self, index):
""" Internal function to load data
This function is used internally by the global __getitem__ function
defined in the base class, which handles moving data around when
the dataset is (for example) storing the data on the CPU but
getting data as GPU tensors.
It loads data in the format (inputs, output)
The inputs for a 2D ptychogaphy data set are:
1) The indices of the patterns to use
2) The recorded probe positions associated with those points
3) The angles of the polarizers if polarized=True
Parameters
----------
index (polarized=False): int or slice
The index or indices of the scan points to use
index (polarized=True):
tuple ((phi1, phi2), ind)
ind - index or indices of the scan points to use (in a (phi1, phi2) polarization state), int or slice
(phi1, phi2) - angles of the 1st and 2nd polarizers, ints
Returns
-------
inputs : tuple
A tuple of the inputs to the related forward models
if polarized: inputs = ((phi1, phi2), ind, transl[(phi1, phi2)][ind])
outputs : tuple
The output pattern or stack of output patterns
"""
return ((index, self.translations[index],
self.polarizer[index], self.analyzer[index]),
self.patterns[index])
def to(self, *args, **kwargs):
"""Sends the relevant data to the given device and dtype
This function sends the stored translations, patterns,
mask and background to the specified device and dtype
Accepts the same parameters as torch.Tensor.to
"""
super(PolarizedPtycho2DDataset, self).to(*args, **kwargs)
self.polarizer = self.polarizer.to(*args, **kwargs)
self.analyzer = self.analyzer.to(*args, **kwargs)
# It sucks that I can't reuse the base factory method here,
# perhaps there is a way but I couldn't figure it out.
@classmethod
def from_cxi(cls, cxi_file, cut_zeros=True):
"""Generates a new PolarizedPtycho2DDataset from a .cxi file directly
This generates a new PolarizedPtycho2DDataset from a .cxi file storing
a 2D ptychography scan.
Parameters
----------
file : str, pathlib.Path, or h5py.File
The .cxi file to load from
cut_zeros : bool
Default True, whether to set all negative data to zero
Returns
-------
dataset : PolarizedPtycho2DDataset
The constructed dataset object
"""
# If a bare string is passed
if isinstance(cxi_file, str) or isinstance(cxi_file, pathlib.Path):
with h5py.File(cxi_file, 'r') as f:
return cls.from_cxi(f, cut_zeros=cut_zeros)
# Generate a base dataset
dataset = Ptycho2DDataset.from_cxi(cxi_file, cut_zeros=cut_zeros)
# Mutate the class to this subclass (PolarizedPtycho2DDataset)
dataset.__class__ = cls
# Now, we save out the polarizer and analyzer states
polarizer = cdtdata.get_shot_to_shot_info(cxi_file, 'polarizer_angle')
analyzer = cdtdata.get_shot_to_shot_info(cxi_file, 'analyzer_angle')
dataset.analyzer = t.tensor(analyzer, dtype=t.float32)
dataset.polarizer = t.tensor(polarizer, dtype=t.float32)
return dataset
def to_cxi(self, cxi_file, polarized=False):
"""Saves out a PolarizedPtycho2DDataset as a .cxi file
This function saves all the compatible information in a
PolarizedPtycho2DDataset object into a .cxi file. This saved .cxi file
should be compatible with any standard .cxi file based
reconstruction tool, such as SHARP.
Parameters
----------
cxi_file : str, pathlib.Path, or h5py.File
The .cxi file to write to
"""
# If a bare string is passed
if isinstance(cxi_file, str) or isinstance(cxi_file, pathlib.Path):
with cdtdata.create_cxi(cxi_file) as f:
return self.to_cxi(f)
# This saves the translations, patterns, etc.
super(PolarizedPtycho2DDataset, self).to_cxi(cxi_file)
# Now, we save out the polarizer and analyzer states
cdtdata.add_shot_to_shot_info(cxi_file, self.polarizer,
'polarizer_angle')
cdtdata.add_shot_to_shot_info(cxi_file, self.analyzer,
'analyzer_angle')
def inspect(self, logarithmic=True, units='um'):
"""Launches an interactive plot for perusing the data
This launches an interactive plotting tool in matplotlib that
shows the spatial map constructed from the integrated intensity
at each position on the left, next to a panel on the right that
can display a base-10 log plot of the detector readout at each
position.
"""
def get_images(idx):
inputs, output = self[idx]
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 logarithmic:
return np.log(meas_data) / np.log(10) * mask
else:
return meas_data * mask
translations = self.translations.detach().cpu().numpy()
nanomap_values = (self.mask.to(t.float32) * self.patterns).sum(dim=(1,2)).detach().cpu().numpy()
if logarithmic:
cbar_title='Log Base 10 of Diffraction Intensity'
else:
cbar_title='Diffraction Intensity'
plotting.plot_nanomap_with_images(self.translations.detach().cpu(), get_images, values=nanomap_values, nanomap_units=units, image_title='Diffraction Pattern', image_colorbar_title=cbar_title)