* add word_ids and simplify
* simplify
* add word_ids to be removed later
* remove word_ids
* seems to work
* tweak
* transpose word_z
* add word_ids example
* check api compatibility
* improve compatibility
* update doc
* tweak verbose
* restore word_z layout; tweak
* tweak
* tweak doc
* word_cT
* use log_weight and some other tweaks
* rewrite README
* update equations
* rewrite for clarity and pass tests
* tweak
* bugfix import
* fix unit test
* fix mult to be the same as old versions
* tweak
* could be a bugfix
* 0/0=nan
* add doc_subgraph utility function
* minor cache optimization
* minor cache tweak
* add environmental variable to trade cache speed for memory
* update README
* tweak
* add sparse update pass unit test
* simplify sparse update
* improve low-memory efficiency
* tweak
* add sample expectation scores to allow resampling
* simplify
* update comment
* avoid edge cases
* bugfix pred scores
* simplify
* add save function
Co-authored-by: Yifei Ma <yifeim@amazon.com>
Co-authored-by: Quan (Andy) Gan <coin2028@hotmail.com>
Co-authored-by: Jinjing Zhou <VoVAllen@users.noreply.github.com>
Andrei Ivanov