NEW: Additional ptychography gradient-based approach using ADAM

[carterbox]

Purpose

Add an additional ptychography solver based on the ADAptive moment gradient descent algorithm. Also adds a constraint which aims to keep probe illuminations centered.

Approach

ADAM is a gradient descent accelerator which uses a momentum and velocity variable (which are the same shape as the gradient) to push the search direction towards directions that often appear in the gradient. These terms provide the search direction with a short-term memory (momentum).

Pre-Merge Checklists

Submitter

• [x] Write a helpfully descriptive pull request title.
• [x] Organize changes into logically grouped commits with descriptive commit messages.
• [x] Document all new functions.
• [x] Write tests for new functions or explain why they are not needed.
• [ ] Build the documentation successfully
• [x] Use yapf to format python code.

Reviewer

• [ ] Actually read all of the code.
• [ ] Run the new code yourself.
• [ ] Write a summary of the changes as you understand them.
• [ ] Thank the submitter.

[pep8speaks]

Hello @carterbox! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file src/tike/ptycho/probe.py:

Line 499:81: E501 line too long (81 > 80 characters)

Comment last updated at 2021-09-30 22:04:16 UTC