blakesanie / Qwerty-Revisited

⌨️ Custom optimal keyboard generator

Qwerty, Revisited

A Node.js program that creates the optimal keyboard for the given text, and compares it to Qwerty.

generation.js

1. Load .txt file, format string by removing all punctuation, numbers, spaces, and moving all letters to lowercase.

   var fs = require('fs');
   var file = "test.txt";
   
   fs.readFile(file, 'utf8', function(err, data) {
       if (err) throw err;
       var text = data.replace(/[^\w\s]|_/g, "").replace(/\s+/g, " ").replace(/[a-z]*\d+[a-z]*/gi, '').replace(/\s+/g, '').toLowerCase();
       processChars(text);
   });

2. Iterate through all characters, each time updating the Markov Chain object. The model contains the frequency of each letter and the frequency of each letter that follows it.

   var markovChain = {};
   
   function processChars(string) {
       for (var i = 0; i <= string.length - order; i++) {
           var gram = string.substring(i, i + order);
           var nextChar = string.charAt(i + order);
           if (!markovChain[gram]) {
               markovChain[gram] = {
                   freq : 0
               };
               markovChain[gram][nextChar] = 0;
           }
           if (!markovChain[gram][nextChar]) {
               markovChain[gram][nextChar] = 0;
           }
           markovChain[gram][nextChar]++;
           markovChain[gram]["freq"]++;
       }
       loadKeys();
   }

3. Divide letters into rows, and test each permutation of the three rows to find the configuration with the lowest probability of adjacent key presses (using Markov Chain). The final keyboard is printed.

   var topRow = [];
   var middleRow = [];
   var bottomRow = [];
   
   function loadKeys() {
       var mostUsed = getMostUsed(); // getMostUsed() not shown
       console.log(mostUsed);
       middleRow = mostUsed.slice(0,9);
       topRow = mostUsed.slice(9,19);
       bottomRow = mostUsed.slice(19);
       optimizeMiddleRow(); //
       optimizeTopRow();    // algorithm not shown, found in source code
       optimizeBottomRow(); //
       printKeys();     //
       printKeyArray(); // output keyboard to console
   }

Other functions can be found in the source code for generation.js

simulation.js

1. Load .txt file, format in same way as before.

   var file = "test.txt";
   
   fs.readFile(file, 'utf8', function(err, data) {
       if (err) throw err;
       text = data.replace(/[^\w\s]|_/g, "").replace(/\s+/g, " ").replace(/[a-z]*\d+[a-z]*/gi, '').replace(/\s+/g, '').toLowerCase();
       //getScore(text)
   });

2. Re-type .txt file, keeping track of each finger's position. Consecutive movements on the same hand have a weight of 1 (slow), whereas movements after switching hands have a weight of 0.5 (fast).

   var fingers = [1,2,3,4,5,5,6,7,8,1,2,3,4,4,5,5,6,7,1,2,3,4,4,5,6]; //index of finger that touches key
   
   function getScore(keyboard) {
       var hands = [1,1,1,1,1,1,1,1]; // 1 = home row, 0 = top, 2 = bottom
       var moves = 0;
       var lastTurnwasLeft = true;
       for (var i = 0; i < text.length; i++) {
           var char = text.charAt(i);
           var key = keyboard.indexOf(char);
           var finger = fingers[key];
           var row = 0;
           if (key > 9) {
               row = 1;
           } 
           if (key > 18) {
               row = 2;
           }
           var handIsLeft = true;
           if (finger > 4) {
               handIsLeft = false;
           }
           if (row != hands[finger]) {
               hands[finger] = row;
               if (handIsLeft == lastTurnwasLeft) {
                   moves++;
               } else {
                   moves += 0.5;
               }
           }
           lastTurnwasLeft = handIsLeft;
       }
       return moves;
   }

3. Calculate efficiency and output to console.

   var qwerty = ["q","w","e","r","t","y","u","i","o","p","a","s","d","f","g","h","j","k","l","z","x","c","v","b","n","m"];
   var mine = ["c","w","b","m","f","g","l","d","u","y","n","h","r","o","i","s","e","t","a","v","q","j","k","x","z","p"];
   // ^ keyboard generated after test.txt
   
   console.log("QWERTY: " + getScore(qwerty));
   console.log("MINE  : " + getScore(mine));
   console.log(Math.round(getScore(qwerty) / getScore(mine) * 100) + "% efficiency \n");