From 5792b9d92e9321eaabf81075ab47be1c5db8ece3 Mon Sep 17 00:00:00 2001
From: AJ ONeal <coolaj86@gmail.com>
Date: Mon, 27 May 2013 22:30:52 -0500
Subject: [PATCH] added hotplate2

---
 hotplate2.js | 188 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 188 insertions(+)
 create mode 100644 hotplate2.js

diff --git a/hotplate2.js b/hotplate2.js
new file mode 100644
index 0000000..f3555c8
--- /dev/null
+++ b/hotplate2.js
@@ -0,0 +1,188 @@
+/*
+ * The hotplat could be represented (6x6) as
+ *
+ *     0 * * * * 0
+ *     * * * * * *
+ *     * * 1 1 * *
+ *     * * 1 1 * *
+ *     * * * * * *
+ *     0 * * * * 0
+ *
+ */
+(function () {
+  "use strict";
+
+  var red   = '\u001b[31m'
+    , yellow  = '\u001b[33m'
+    , blue  = '\u001b[34m'
+    , reset = '\u001b[0m'
+    ;
+  function pad(num) {
+    num = String(num);
+
+    while (num.length < 6) {
+      num = ' ' + num;
+    }
+
+    return num;
+  }
+  /*
+   * rows: number of rows
+   * cols: number of columns
+   * diff: maximum allowable difference
+   * initial: the start value of each cell
+   * turns: maximum number of turns
+   */
+  function HotPlate(opts) {
+    var me = this
+      ;
+      
+    me.numrows = opts.rows;
+    me.numcols = opts.cols;
+    me.prevRows = [];
+    me.nextRows = [];
+    me.maxDiff = opts.diff || 0.00001;
+    me.maxTurns = opts.turns || 100 * 1000;
+
+    me.initializeGrid(me.prevRows);
+    me.initializeGrid(me.nextRows);
+
+    //console.log(me.prevRows);
+    //console.log(me.nextRows);
+  }
+
+  HotPlate.prototype.initializeGrid = function (rows) {
+    var me = this
+      , row
+      , i
+      , j
+      ;
+
+    for (i = 0; i < me.numrows; i += 1) {
+      row = [];
+      rows.push(row);
+      for (j = 0; j < me.numcols; j += 1) {
+        row.push(me.initial || 0);
+      }
+    }
+
+    // 0, 1, 2, [3, 4], 5, 6, 7
+    rows[(me.numrows / 2) - 1][(me.numcols / 2) - 1] = 100;
+    rows[(me.numrows / 2) - 1][(me.numcols / 2)] = 100;
+    rows[(me.numrows / 2)][(me.numcols / 2) - 1] = 100;
+    rows[(me.numrows / 2)][(me.numcols / 2)] = 100;
+  };
+
+  HotPlate.prototype.run = function () {
+    var me = this
+      , diff = 100
+      , sum
+      , count
+      , i
+      , j
+      , rows
+      , turns = 0
+      , str
+      , color
+      ;
+
+    while (diff > me.maxDiff && turns < me.maxTurns) {
+      turns += 1;
+      diff = 0;
+
+      for (i = 0; i < me.numrows; i += 1) {
+        for (j = 0; j < me.numcols; j += 1) {
+          // ignore the cold cells (cornermost)
+          if (
+                 (i === 0 && j === 0)
+              || (i === 0 && j === me.numcols - 1)
+              || (i === me.numrows - 1 && j === 0)
+              || (i === me.numrows - 1 && j === me.numcols - 1)
+          ) {
+            continue;
+          }
+
+          // ignore hot cells (centermost)
+          if (
+                 (i === (me.numrows / 2) - 1 && j === (me.numcols / 2) - 1)
+              || (i === (me.numrows / 2) - 1 && j === (me.numcols / 2))
+              || (i === (me.numrows / 2) && j === (me.numcols / 2) - 1)
+              || (i === (me.numrows / 2) && j === (me.numcols / 2))
+          ) {
+            continue;
+          }
+
+          // add up, left, right, down and self values
+          // (but only if they exist)
+          rows = me.prevRows;
+          //console.log(rows);
+          sum = 0;
+          count = 0;
+          if (i > 0) {
+            count += 1;
+            sum += rows[i - 1][j];
+            //console.log('i>0:', rows[i - 1] + rows[j]);
+          }
+          if (i < me.numrows - 1) {
+            count += 1;
+            sum += rows[i + 1][j];
+            //console.log('i<last:', rows[i + 1] + rows[j]);
+          }
+          if (j > 0) {
+            count += 1;
+            sum += rows[i][j - 1];
+            //console.log('j>0:', rows[i] + rows[j - 1]);
+          }
+          if (j < me.numcols - 1) {
+            count += 1;
+            sum += rows[i][j + 1];
+            //console.log('j<last:', rows[i] + rows[j + 1]);
+          }
+
+          /*
+          console.log(
+              'i:' + i
+            , 'j:' + j
+            , 'i,j:' + me.nextRows[i][j]
+            , 'sum:' + sum
+            , 'count:' + count
+            , 'avg:' + sum / count
+          );
+          */
+          me.nextRows[i][j] = sum / count;
+
+          diff = Math.max(diff, Math.abs(me.nextRows[i][j] - me.prevRows[i][j]));
+        }
+      }
+
+      me.prevRows = me.nextRows;
+      me.nextRows = [];
+      me.initializeGrid(me.nextRows);
+    }
+
+    console.log('Grid:', me.numrows + 'x' + me.numcols);
+    console.log('Turns:', turns);
+    console.log('Diff:', me.maxDiff);
+    for (i = 0; i < me.numrows; i += 1) {
+      str = '';
+      for (j = 0; j < me.numcols; j += 1) {
+        if (me.prevRows[i][j] < 33) {
+          color = blue;
+        } else if (me.prevRows[i][j] > 66) {
+          color = red;
+        } else {
+          color = yellow;
+        }
+        str += ' ' + color + pad((me.prevRows[i][j]).toFixed(2));
+      }
+      console.log(str);
+    }
+    console.log(reset + 'Actual Diff:', diff);
+  };
+
+  HotPlate.create = function (opts) {
+    return new HotPlate(opts);
+  };
+
+  HotPlate.create({ cols: 8, rows: 16}).run();
+}());