Fix/clip post-lapse stability (#30)

open-spaced-repetition · Dec 17, 2024 · b442a7c · b442a7c
1 parent 20a712d
commit b442a7c
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Showing 2 changed files with 3 additions and 2 deletions.
diff --git a/scheduler_basic.go b/scheduler_basic.go
@@ -139,7 +139,8 @@ func (bs basicScheduler) reviewState(grade Rating) SchedulingInfo {
 
 func (bs basicScheduler) nextDs(nextAgain, nextHard, nextGood, nextEasy *Card, difficulty, stability, retrievability float64) {
 	nextAgain.Difficulty = bs.parameters.nextDifficulty(difficulty, Again)
-	nextAgain.Stability = bs.parameters.nextForgetStability(difficulty, stability, retrievability)
+	nextSMin := stability / math.Exp(bs.parameters.W[17]*bs.parameters.W[18])
+	nextAgain.Stability = math.Min(nextSMin, bs.parameters.nextForgetStability(difficulty, stability, retrievability))
 
 	nextHard.Difficulty = bs.parameters.nextDifficulty(difficulty, Hard)
 	nextHard.Stability = bs.parameters.nextRecallStability(difficulty, stability, retrievability, Hard)

diff --git a/scheduler_longterm.go b/scheduler_longterm.go
@@ -85,7 +85,7 @@ func (lts longTermScheduler) reviewState(grade Rating) SchedulingInfo {
 
 func (lts longTermScheduler) nextDs(nextAgain, nextHard, nextGood, nextEasy *Card, difficulty, stability, retrievability float64) {
 	nextAgain.Difficulty = lts.parameters.nextDifficulty(difficulty, Again)
-	nextAgain.Stability = lts.parameters.nextForgetStability(difficulty, stability, retrievability)
+	nextAgain.Stability = math.Min(stability, lts.parameters.nextForgetStability(difficulty, stability, retrievability))
 
 	nextHard.Difficulty = lts.parameters.nextDifficulty(difficulty, Hard)
 	nextHard.Stability = lts.parameters.nextRecallStability(difficulty, stability, retrievability, Hard)