diff options
| -rw-r--r-- | gnosis.el | 83 |
1 files changed, 82 insertions, 1 deletions
@@ -163,11 +163,92 @@ use it like this: rev_log rev_score]))) -;; Gnosis mode +;; Gnosis mode ;; +;;;;;;;;;;;;;;;;; + (define-derived-mode gnosis-mode special-mode "Gnosis" "Gnosis Mode." :interactive t (display-line-numbers-mode 0) :lighter " gnosis-mode") +;; Gnosis Algorithm ;; +;;;;;;;;;;;;;;;;;;;;;; + +(defcustom gnosis-interval '(1 3) + "Gnosis algorithm interval. +- Interval by which a new question is displayed or when it's ef is at 1.3. +First item: First interval +Second item: Second interval. + +e.g if you use: + (setq gnosis-interval '(2 4)) +Upon successfully recalling a question, it's next interval will be in +2 days. Recalling the same question successfully in 2 days, will put +it's interval at 4 days, afterwards it's next interval will be calculated using `gnosis-ef'." + :group 'gnosis + :type 'list) + +(defcustom gnosis-ef '(0.2 0.2) + "Gnosis easiness factor. + +First item : Increase factor +Second item: Decrease factor" + :group 'gnosis + :type 'list) + +(defcustom gnosis-ff 0.5 + "Gnosis forgetting factor. + +Used to calcuate new interval for failed questions." + :group 'gnosis + :type 'float) + +(defun gnosis-calculate-e-factor (ef quality) + "Calculate new e-factor given existing EF and binary QUALITY, 0 or 1." + (cond + ((not (numberp quality)) + (error "Invalid argument passed to gnosis-calculate-e-factor")) + ((= quality 0) ;; If the quality score is 0 (fail), decrease the ef by a small penalty + (max 1.3 (- ef (cadr gnosis-ef)))) + ((= quality 1) ;; If the quality score is 1 (pass), increase the ef by a small reward + (+ ef (car gnosis-ef))) + (t (error "Invalid quality score passed to gnosis-calculate-e-factor")))) + +(defun gnosis-calculate-next-interval (last-interval n ef success ff) + "Calculate next interval. +- LAST-INTERVAL : The number of days since the item was last reviewed. +- N : Number of times the item has been reviewed. +- EF : The 'easiness factor'. +- SUCCESS : Success of the recall, ranges from 0 (unsuccessful) to 1 + (successful). +- FF: Failure factor + +Returns a tuple: (INTERVAL N EF) where, +- INTERVAL : The number of days until the item should next be reviewed. +- N : Incremented by 1. +- EF : Modified based on the recall success for the item." + ;; Ensure valid parameters. + ;; (cl-assert (> n 0)) + (cl-assert (and (>= success 0) + (<= success 1))) + ;; Calculate the next easiness factor. + (let* ((next-ef (gnosis-calculate-e-factor ef success)) + ;; Calculate the next interval. + (interval + (cond + ;; If ef is 1.3, repeat question in the same day. + ((= ef 1.3) 0) + ;; Immediately next day if it's the first time review. + ((<= n 1) (car gnosis-interval)) + ;; After 3 days if it's second review. + ((= n 2) (cadr gnosis-interval)) + ;; Increase last interval by 1 if recall was successful. Keep last interval if unsuccessful. + (t (if (= success 1) + (* ef last-interval) + (* ff last-interval)))))) + (list (round interval) (1+ n) next-ef))) + + +(provide 'gnosis) ;;; gnosis.el ends here |