open-spaced-repetition / fsrs4anki

A modern Anki custom scheduling based on Free Spaced Repetition Scheduler algorithm
https://github.com/open-spaced-repetition/fsrs4anki/wiki
MIT License
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[Question] Wiki—post-lapse stability example parameter inconsistency? #662

Closed djliden closed 4 months ago

djliden commented 4 months ago

Do you have a doubt about using FSRS in Anki? If so, please post on https://forums.ankiweb.net/ instead.

This issue tracker is primarily intended for questions and suggestions about the algorithm itself, rather than its usage in Anki. In addition, a larger community can provide support on the Anki Forums.

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Question

The post-lapse stability example under the FSRS v4 header appears to use the default parameters from the FSRS v3 section, not those from the v4 section.

e.g. $S^\prime_f(S=100) = 2\cdot 2^{-0.2} \cdot ((100+1)^{0.2}-1) \cdot e^{1(1-0.9)} \approx 3$

corresponds to the params in this list from v3: var w = [1, 1, 5, -1, -1, 0.1, 1.5, -0.2, 0.8, 2, -0.2, 0.2, 1];

where I'd have expected to use w_11–w_14 = 2.18, 0.05, 0.34, 1.26.

Is this an error in the wiki, or am I understanding this incorrectly? Thank you!

L-M-Sherlock commented 4 months ago

The parameters are selected arbitrarily.