From 5d69e1865abe2e2d721c22a606b3e2e18ddbd638 Mon Sep 17 00:00:00 2001 From: Thanos Apollo Date: Mon, 18 Dec 2023 02:51:37 +0200 Subject: Seperate gnosis-algorithm from gnosis.el --- gnosis-algorithm.el | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 gnosis-algorithm.el (limited to 'gnosis-algorithm.el') diff --git a/gnosis-algorithm.el b/gnosis-algorithm.el new file mode 100644 index 0000000..5cbca92 --- /dev/null +++ b/gnosis-algorithm.el @@ -0,0 +1,127 @@ +;;; gnosis-algorithm.el --- Spaced Repetition Algorithm for Gnosis -*- lexical-binding: t; -*- + +;; Copyright (C) 2023 Thanos Apollo + +;; Author: Thanos Apollo +;; Keywords: extensions +;; URL: https://git.thanosapollo.org/gnosis +;; Version: 0.0.1 + +;; Package-Requires: ((emacs "27.2") (compat "29.1.4.2")) + +;; This program is free software; you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation, either version 3 of the License, or +;; (at your option) any later version. + +;; This program is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with this program. If not, see . + +;;; Commentary: + +;; Work in progress + +;;; Code: + +(require 'cl-lib) +(require 'calendar) + +(defcustom gnosis-interval '(1 3) + "Gnosis initial 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." + :group 'gnosis + :type 'list) + +(defcustom gnosis-algorithm-ef '(0.3 0.3) + "Gnosis easiness factor. + +First item : Increase factor +Second item: Decrease factor" + :group 'gnosis + :type 'list) + +(defcustom gnosis-algorithm-ff 0.5 + "Gnosis forgetting factor. + +Used to calcuate new interval for failed questions." + :group 'gnosis + :type 'float) + + +(defun gnosis-algorithm-date (&optional offset) + "Return the current date in a list (year month day). +Optional integer OFFSET is a number of days from the current date." + (let* ((now (decode-time)) + (now (list (decoded-time-month now) + (decoded-time-day now) + (decoded-time-year now)))) + (let ((date (if (zerop (or offset 0)) + now + (calendar-gregorian-from-absolute + (+ offset (calendar-absolute-from-gregorian now)))))) + (list (nth 2 date) (nth 0 date) (nth 1 date))))) + + +(defun gnosis-algorithm-date-diff (year month day) + "Find the difference between the current date and the given date. + +The structure of the given date is (YEAR MONTH DAY)." + (let ((current-date (gnosis-algorithm-date)) + (given-date (encode-time 0 0 0 day month year))) + (- (time-to-days (current-time)) + (time-to-days given-date)))) + +(defun gnosis-algorithm-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-algorithm-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-algorithm-e-factor")))) + +(defun gnosis-algorithm-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 : 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." + (cl-assert (and (>= success 0) + (<= success 1))) + ;; Calculate the next easiness factor. + (let* ((next-ef (gnosis-algorithm-e-factor ef success)) + ;; Calculate the next interval. + (interval + (cond + ;; Show item same day on the first review + ((= n 0) 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-algorithm) +;;; gnosis-algorithm.el ends here -- cgit v1.2.3