rpsls.js

   1 const nChoice = 3; //fixed for this game
   2
   3 // Rewards matrix. Order: rock, lizard, Spock, scissors, paper
   4 const rewards = Array.from(Array(nChoice)).map( (e,i) => { //lines
   5     return Array.from(Array(nChoice)).map( (f,j) => { //columns
   6         // i against j: gain from i viewpoint
   7         if (j == (i+1) % nChoice)// || j == (i+3) % nChoice)
   8             return 1; //I win :)
   9         else if (i != j)
  10             return -1; //I lose :(
  11         else //i == j
  12             return 0;
  13     });
  14 });
  15
  16 const symbols = [ "Rock", "Lizard", "Spock", "Scissors", "Paper" ];
  17
  18 new Vue({
  19     el: "#rpsls",
  20     data: {
  21         humanMove: -1, //integer in 0...nChoice-1
  22         nInput: 5, //default
  23         humanHistory: [ ], //your nInput last moves, stored (oldest first)
  24         gameState: 0, //total points of the computer
  25         drawIsLost: false, //normal (or true: draw is considered loss)
  26         rewards: [ ], //initialized at first human move with new nInput
  27         weights: [ ], //same as above
  28     },
  29     created: function() {
  30         this.reinitialize();
  31     },
  32     methods: {
  33         // Called on nInput change
  34         reinitialize: function() {
  35             // weights[i][j][k]: output i -- input j/choice k
  36             this.weights = Array.from(Array(nChoice)).map( i => {
  37                 return Array.from(Array(this.nInput)).map( j => {
  38                     return Array.from(Array(nChoice)).map( k => {
  39                         return 0;
  40                     });
  41                 })
  42             });
  43             if (this.humanHistory.length > this.nInput)
  44                 this.humanHistory.splice(this.nInput);
  45         },
  46         // Play a move given current data (*after* human move: trigger onChange)
  47         play: function() {
  48             let candidates = [ ];
  49             Array.from(Array(nChoice)).forEach( (e,i) => {
  50                 // Sum all weights from an activated input to this output
  51                 let sumWeights = this.weights[i].reduce( (acc,input,j) => {
  52                     if (this.humanHistory.length <= j)
  53                         return 0;
  54                     return input[ this.humanHistory[j] ];
  55                 }, 0 );
  56                 let currentValue = {
  57                     val: sumWeights,
  58                     index: i
  59                 };
  60                 if (candidates.length == 0 || sumWeights > candidates[0].val)
  61                     candidates = [ currentValue ];
  62                 else if (sumWeights == candidates[0].val)
  63                     candidates.push(currentValue);
  64             });
  65             // Pick a choice at random in maxValue (total random for first move)
  66             let randIdx = Math.floor((Math.random() * candidates.length) + 1);
  67             this.updateGameState(candidates[randIdx].index);
  68         },
  69         updateGameState: function(index) {
  70             let reward = rewards[index][this.humanMove]; //viewpoint of computer
  71             this.gameState += reward;
  72             this.updateWeights(reward, index);
  73         },
  74         updateWeights: function(reward, index) {
  75             let delta = Math.sign(reward);
  76             if (this.drawIsLost && reward == 0)
  77                 delta = -1;
  78             this.weights[index].forEach( (input,i) => {
  79                 if (i < this.humanHistory.length)
  80                     input[ this.humanHistory[i] ] += delta;
  81             });
  82             this.postUpdate();
  83         },
  84         // Finalize weights update
  85         postUpdate: function() {
  86             // Re-center the weights
  87             let sumAllWeights = this.weights.reduce( (a,output) => {
  88                 return a + output.reduce( (b,input) => {
  89                     return b + input.reduce( (c,choiceWeight) => {
  90                         return c + choiceWeight;
  91                     }, 0);
  92                 }, 0);
  93             }, 0);
  94             let meanWeight = sumAllWeights / (this.nInput * nChoice * nChoice);
  95             this.weights.forEach( output => {
  96                 output.forEach( input => {
  97                     for (let i=0; i<input.length; i++)
  98                         input[i] -= meanWeight;
  99                 });
 100             });
 101             // Update human moves history
 102             this.humanHistory.push(this.humanMove);
 103             if (this.humanHistory.length > this.nInput)
 104                 this.humanHistory.shift();
 105         },
 106   },
 107 });