Merge pull request #42 from mikebryant/integrating-probability

feat: Integrating probability

index.html

@@ -37,6 +37,33 @@
         </span>
       </div>
     </div>
+    <div class="row">
+      <div class="col s12">
+        <h5>Probability</h5>
+        <div class="row">
+          <div class="col s4">
+            <div class="input-field">
+              <select id="previous_pattern">
+                <option value="-1" selected>(unknown)</option>
+                <!-- Choices are ordered by increasing desirability, not code ID order -->
+                <option value="2">Decreasing</option>
+                <option value="0">Fluctuating</option>
+                <option value="3">Small spike</option>
+                <option value="1">Large spike</option>
+              </select>
+              <label for="previous_pattern">Last week’s pattern</label>
+            </div>
+          </div>
+          <div class="col s6">
+            <div class="input-field">
+              <span>
+                <b>Last week’s pattern</b> affects the probability of patterns for this week. If you know it, select it to see probabilities for this week. <em>(optional)</em>
+              </span>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
     <div class="row">
       <div class="col s12">
         <h5>Daisy Mae</h5>
@@ -152,6 +179,7 @@
         <thead>
           <tr>
             <th rowspan="2">Pattern</th>
+            <th rowspan="2">% Chance</th>
             <th rowspan="2">Sunday</th>
             <th colspan="2">Monday</th>
             <th colspan="2">Tuesday</th>

js/predictions.js

@@ -1,3 +1,44 @@
+const PATTERN = {
+  FLUCTUATING: 0,
+  LARGE_SPIKE: 1,
+  DECREASING: 2,
+  SMALL_SPIKE: 3,
+};
+
+const PATTERN_COUNTS = {
+  [PATTERN.FLUCTUATING]: 56,
+  [PATTERN.LARGE_SPIKE]: 7,
+  [PATTERN.DECREASING]: 1,
+  [PATTERN.SMALL_SPIKE]: 8,
+}
+
+const PROBABILITY_MATRIX = {
+  [PATTERN.FLUCTUATING]: {
+    [PATTERN.FLUCTUATING]: 0.20,
+    [PATTERN.LARGE_SPIKE]: 0.30,
+    [PATTERN.DECREASING]: 0.15,
+    [PATTERN.SMALL_SPIKE]: 0.35,
+  },
+  [PATTERN.LARGE_SPIKE]: {
+    [PATTERN.FLUCTUATING]: 0.50,
+    [PATTERN.LARGE_SPIKE]: 0.05,
+    [PATTERN.DECREASING]: 0.20,
+    [PATTERN.SMALL_SPIKE]: 0.25,
+  },
+  [PATTERN.DECREASING]: {
+    [PATTERN.FLUCTUATING]: 0.25,
+    [PATTERN.LARGE_SPIKE]: 0.45,
+    [PATTERN.DECREASING]: 0.05,
+    [PATTERN.SMALL_SPIKE]: 0.25,
+  },
+  [PATTERN.SMALL_SPIKE]: {
+    [PATTERN.FLUCTUATING]: 0.45,
+    [PATTERN.LARGE_SPIKE]: 0.25,
+    [PATTERN.DECREASING]: 0.15,
+    [PATTERN.SMALL_SPIKE]: 0.15,
+  },
+};
+
 function minimum_rate_from_given_and_base(given_price, buy_price) {
   return 10000 * (given_price - 1) / buy_price;
 }
@@ -177,7 +218,7 @@ function* generate_pattern_0_with_lengths(given_prices, high_phase_1_len, dec_ph
     });
   }
   yield {
-    pattern_description: "high, decreasing, high, decreasing, high",
+    pattern_description: "Fluctuating",
     pattern_number: 0,
     prices: predicted_prices
   };
@@ -285,7 +326,7 @@ function* generate_pattern_1_with_peak(given_prices, peak_start) {
     });
   }
   yield {
-    pattern_description: "decreasing middle, high spike, random low",
+    pattern_description: "Large spike",
     pattern_number: 1,
     prices: predicted_prices
   };
@@ -351,7 +392,7 @@ function* generate_pattern_2(given_prices) {
     max_rate -= 300;
   }
   yield {
-    pattern_description: "consistently decreasing",
+    pattern_description: "Decreasing",
     pattern_number: 2,
     prices: predicted_prices
   };
@@ -531,7 +572,7 @@ function* generate_pattern_3_with_peak(given_prices, peak_start) {
   }
 
   yield {
-    pattern_description: "decreasing, spike, decreasing",
+    pattern_description: "Small spike",
     pattern_number: 3,
     prices: predicted_prices
   };
@@ -564,8 +605,30 @@ function* generate_possibilities(sell_prices, first_buy) {
   }
 }
 
-function analyze_possibilities(sell_prices, first_buy) {
+function row_probability(possibility, previous_pattern) {
+  return PROBABILITY_MATRIX[previous_pattern][possibility.pattern_number] / PATTERN_COUNTS[possibility.pattern_number];
+}
+
+function get_probabilities(possibilities, previous_pattern) {
+  if (typeof previous_pattern === 'undefined' || Number.isNaN(previous_pattern) || previous_pattern === null || previous_pattern < 0 || previous_pattern > 3) {
+    return possibilities
+  }
+
+  var max_percent = possibilities.map(function (poss) {
+    return row_probability(poss, previous_pattern);
+  }).reduce(function (prev, current) {
+    return prev + current;
+  }, 0);
+
+  return possibilities.map(function (poss) {
+    poss.probability = row_probability(poss, previous_pattern) / max_percent;
+    return poss;
+  });
+}
+
+function analyze_possibilities(sell_prices, first_buy, previous_pattern) {
   generated_possibilities = Array.from(generate_possibilities(sell_prices, first_buy));
+  generated_possibilities = get_probabilities(generated_possibilities, previous_pattern);
 
   global_min_max = [];
   for (var day = 0; day < 14; day++) {
@@ -585,7 +648,7 @@ function analyze_possibilities(sell_prices, first_buy) {
   }
 
   generated_possibilities.push({
-    pattern_description: "predicted min/max across all patterns",
+    pattern_description: "All patterns",
     pattern_number: 4,
     prices: global_min_max,
   });

js/scripts.js

@@ -10,10 +10,12 @@ const getSellFields = function () {
 const sell_inputs = getSellFields()
 const buy_input = $("#buy")
 const first_buy_field = $("#first_buy");
+const previous_pattern_input = $("#previous_pattern");
 
 //Functions
-const fillFields = function (prices, first_buy) {
+const fillFields = function (prices, first_buy, previous_pattern) {
   first_buy_field.prop("checked", first_buy);
+  previous_pattern_input.val(previous_pattern);
 
   buy_input.focus();
   buy_input.val(prices[0] || '')
@@ -36,10 +38,11 @@ const initialize = function () {
   try {
     const prices = getPrices()
     const first_buy = getFirstBuyState();
+    const previous_pattern = getPreviousPatternState();
     if (prices === null) {
-      fillFields([], first_buy)
+      fillFields([], first_buy, previous_pattern)
     } else {
-      fillFields(prices, first_buy)
+      fillFields(prices, first_buy, previous_pattern)
     }
     $(document).trigger("input");
   } catch (e) {
@@ -48,15 +51,19 @@ const initialize = function () {
 
   $("#reset").on("click", function () {
     first_buy_field.prop('checked', false);
+    $("select").val(null);
     $("input").val(null).trigger("input");
   })
+
+  $('select').formSelect();
 }
 
-const updateLocalStorage = function (prices, first_buy) {
+const updateLocalStorage = function (prices, first_buy, previous_pattern) {
   try {
     if (prices.length !== 14) throw "The data array needs exactly 14 elements to be valid"
     localStorage.setItem("sell_prices", JSON.stringify(prices))
     localStorage.setItem("first_buy", JSON.stringify(first_buy));
+    localStorage.setItem("previous_pattern", JSON.stringify(previous_pattern));
   } catch (e) {
     console.error(e)
   }
@@ -71,6 +78,10 @@ const getFirstBuyState = function () {
   return JSON.parse(localStorage.getItem('first_buy'))
 }
 
+const getPreviousPatternState = function () {
+  return JSON.parse(localStorage.getItem('previous_pattern'))
+}
+
 const getPricesFromLocalstorage = function () {
   try {
     const sell_prices = JSON.parse(localStorage.getItem("sell_prices"));
@@ -112,14 +123,15 @@ const getSellPrices = function () {
   })
 }
 
-const calculateOutput = function (data, first_buy) {
+const calculateOutput = function (data, first_buy, previous_pattern) {
   if (isEmpty(data)) {
     $("#output").html("");
     return;
   }
   let output_possibilities = "";
-  for (let poss of analyze_possibilities(data, first_buy)) {
+  for (let poss of analyze_possibilities(data, first_buy, previous_pattern)) {
     var out_line = "<tr><td>" + poss.pattern_description + "</td>"
+    out_line += `<td>${Number.isFinite(poss.probability) ? ((poss.probability * 100).toPrecision(3) + '%') : '—'}</td>`;
     for (let day of poss.prices.slice(1)) {
       if (day.min !== day.max) {
         out_line += `<td>${day.min}..${day.max}</td>`;
@@ -138,15 +150,17 @@ const update = function () {
   const sell_prices = getSellPrices();
   const buy_price = parseInt(buy_input.val());
   const first_buy = first_buy_field.is(":checked");
+  const previous_pattern = parseInt(previous_pattern_input.val());
 
   buy_input.prop('disabled', first_buy);
 
   const prices = [buy_price, buy_price, ...sell_prices];
   if (!window.price_from_query) {
-    updateLocalStorage(prices, first_buy);
+    updateLocalStorage(prices, first_buy, previous_pattern);
   }
-  calculateOutput(prices, first_buy);
+  calculateOutput(prices, first_buy, previous_pattern);
 }
 
 $(document).ready(initialize);
 $(document).on("input", update);
+$(previous_pattern_input).on("change", update);