04. Resume Reconstruction

04. Resume Reconstruction#

Description of this walkthrough goes here.

 1# Created with PtyRAD 0.1.0b13
 2# Documentation: https://ptyrad.readthedocs.io/en/latest/
 3# Detailed description for each option: https://ptyrad.readthedocs.io/en/latest/_autosummary/ptyrad.params.html
 4
 5# Load previous object / probe / positions to resume reconstrucitons
 6
 7# tBL_WSe2
 8
 9init_params:
10    # Experimental params
11    probe_kv               : 80 # [kV] Acceleration voltage
12    probe_conv_angle       : 24.9 # [mrad] Semi-convergence angle for probe-forming aperture
13    probe_aberrations      : {'C10': 0} # [Angstrom, degree] Aberration coefficients in Krivanel polar notations. C10 = -df, and positive C10 refers to overfocus (stronger lens).  
14    meas_Npix              : 128 # Detector pixel number, EMPAD is 128. Only supports square detector for simplicity
15    pos_N_scan_slow        : 128 # Number of scan position along slow scan direction. Usually it's the vertical direction of acquisition GUI
16    pos_N_scan_fast        : 128 # Number of scan position along fast scan direction. Usually it's the horizontal direction of acquisition GUI
17    pos_scan_step_size     : 0.4290 # [Angstrom] Step size between probe positions in a rectangular raster scan pattern
18    # Model complexity
19    probe_pmode_max        : 6 # Maximum number of mixed probe modes
20    obj_Nlayer             : 6 # Number of slices for multislice object
21    obj_slice_thickness    : 2 # [Angstrom] Slice thickness (propagation distance) for multislice ptychography. Typical values are between 1 to 20 Ang.
22    # Preprocessing
23    meas_permute           : null # Permute meas array with a list of ints to reorder datasets into (N_scans, ky, kx) if needed.
24    meas_reshape           : null # Reshape meas array with a list of 3 ints to convert the 4D diffraction dataset (Ry,Rx,ky,kx) into 3D (N_scans,ky,kx) for PtyRAD.
25    meas_flipT             : [1,0,0] # Flip meas orientation with a list of 3 binary booleans (0 or 1) as [flipud, fliplr, transpose]
26    pos_scan_affine        : null # Affine transformation [scale, asymmetry, rotation, shear] of scan patterns. e.g, [1,0,3,0], rotation and shear are in unit of degree.
27    # Input source and params
28    meas_params            : {'path': 'data/tBL_WSe2/Panel_g-h_Themis/scan_x128_y128.raw', 'key': null} # Supports EMPAD .raw, .hdf5, .mat, and .tif
29    
30    ## NOTE: Resuming previous reconstructions in PtyRAD is very straight-forward.
31    ##       Simply provide the source and path of each component (probe, positions, and object),
32    ##       then they will be initialized independently, so users can refine their object while using a fresh probe,
33    ##       or use an object from PtychoShelves but pair it with a probe from PtyRAD.
34    ##       While PtyRAD will do necessary preprocessing, the sampling (i.e., px size) must be compatible for each loaded component.
35    probe_source           : 'PtyRAD' # Data source of the probe. Currently supporting 'simu', 'PtyRAD', 'PtyShv', 'py4DSTEM', and 'custom'
36    probe_params           : 'output/walkthrough/01_multi_slice/full_N16384_dp128_flipT100_random32_p6_1obj_6slice_dz2_orblur0.4_ozblur1.0/model_iter0200.hdf5' # Provide a str path of 'path/to/reconstruction_model.hdf5'
37    pos_source             : 'PtyRAD' # Data source of the probe positions. Currently supporting 'simu', 'PtyRAD', 'PtyShv', 'py4DSTEM', 'foldslice_hdf5', and 'custom'
38    pos_params             : 'output/walkthrough/01_multi_slice/full_N16384_dp128_flipT100_random32_p6_1obj_6slice_dz2_orblur0.4_ozblur1.0/model_iter0200.hdf5' # Provide a str path of 'path/to/reconstruction_model.hdf5'
39    obj_source             : 'PtyRAD' # Data source of the object. Currently supporting 'simu', 'PtyRAD', 'PtyShv', 'py4DSTEM', and 'custom'
40    obj_params             : 'output/walkthrough/01_multi_slice/full_N16384_dp128_flipT100_random32_p6_1obj_6slice_dz2_orblur0.4_ozblur1.0/model_iter0200.hdf5' # Provide a str path of 'path/to/reconstruction_model.hdf5'
41
42loss_params:
43    loss_single: {'state': true, 'weight': 1.0, 'dp_pow': 0.5} # Amplitude noise model for typical dataset (dose-sufficient) under the maximum-likelihood formalism
44    loss_sparse: {'state': true, 'weight': 0.1, 'ln_order': 1} # L_n norm sparsity regularization calculated for object phase ('objp')
45
46constraint_params:
47    obj_zblur     : {'start_iter': 1,    'step': 1, 'end_iter': null, 'obj_type': 'both', 'kernel_size': 5, 'std': 1} # Apply a "z-direction" 1D Gaussian blur to the object.
48    objp_postiv   : {'start_iter': 1,    'step': 1, 'end_iter': null, 'relax': 0} # Apply a positivity constraint of the object phase by clipping negative values
49
50recon_params:
51    NITER: 200 # Total number of reconstruction iterations. 1 iteration means a full pass of all selected diffraction patterns.
52    BATCH_SIZE: {'size': 32, 'grad_accumulation': 1} # Number of diffraction patterns processed simultaneously to get the gradient update.
53    SAVE_ITERS: 10 # Number of completed iterations before saving the current reconstruction results (model, probe, object) and summary figures.
54    output_dir: 'output/walkthrough/04_resume_reconstruction/'
55    recon_dir_affixes: ['minimal', 'constraint', 'loss'] # Customizable affixes of reconstruction folder name with presets like 'minimal', 'default', 'all'. See docs for 19 more detailed controls.
56    prefix_time: false # type: boolean, preset strings, and time format strings. Set to true to prepend a date str like '20240903_' in front of the reconstruction folder name
57
58    ## NOTE: PtyRAD generates the output folder name based on reconstruction conditions.
59    ##       If resuming the exact same condition, the original result might get overridden.
60    ##       In order to keep the full record, it's recommended to slightly postfix the output folder name to prevent colision.
61    ##       In this example, the original output folder is "01_multislice/full_N16384_dp128_flipT100_random32_p6_1obj_6slice_dz2/"
62    ##       After postfixing the customizable string, the new folder becomes "04_resume_reconstruction/full_N16384_dp128_flipT100_random32_p6_1obj_6slice_dz2_r2/"
63    prefix: '' # Prefix this string to the reconstruction folder name. Note that a "_" will be automatically generated.
64    postfix: 'r2' # Postfix this string to the reconstruction folder name. Note that a "_" will be automatically generated.