fixes to Making Change in preparation for next lesson

EditDistance/src/editDistance.js

@@ -1,7 +1,3 @@
-// Note: The metric used here is Damerau–Levenshtein distance.
-// This metric imposes a uniform cost for insertion, deletion,
-// substitutions, and transposition, as these compose the most
-// common human typing mistakes.
 var editDistance = function(str1, str2) {
   if (str1 === str2) {
     return 0;
@@ -11,47 +7,42 @@ var editDistance = function(str1, str2) {
     return str1.length || str2.length;
   }
 
-  if (str2.length > str1.length) {
-    var temp = str1;
-    str1 = str2;
-    str2 = temp;
-  }
-
   var len1 = str1.length;
   var len2 = str2.length;
 
-  var prevPrevRow;
-  var prevRow = [];
+  // Set up the matrix.
+  var matrix = [];
+  for (var row = 0; row <= len1; row++) {
+    var arr = new Array(len2 + 1);
+    matrix.push(arr);
+  }
+
+  for (var row = 0; row <= len1; row++) {
+    matrix[row][0] = row;
+  }
 
-  // Fill in previous row with empty subsequences.
   for (var col = 0; col <= len2; col++) {
-    prevRow[col] = col;
+    matrix[0][col] = col;
   }
-  var currRow = [1];
 
-  // Fake iterating through the whole matrix,
-  // but remembering only two rows at a time.
   for (var row = 1; row <= len1; row++) {
     for (var col = 1; col <= len2; col++) {
 
       // If two strings match at their final character, their LCS
       // is the LCS of their prefixes, plus that final character.
       if (str1[row-1] === str2[col-1]) {
-        currRow[col] = prevRow[col-1];
+        matrix[row][col] = matrix[row-1][col-1];
 
       // Otherwise, their LCS is the best LCS that results from
       // trimming either of their final characters, plus one.
       } else {
-        var del = prevRow[col] + 1;
-        var ins = currRow[col-1] + 1;
-        var sub = prevRow[col-1] + 1;
-        currRow[col] = Math.min(del, ins, sub);
+        var del = matrix[row-1][col];
+        var ins = matrix[row][col-1];
+        var sub = matrix[row-1][col-1];
+        matrix[row][col] = Math.min(del, ins, sub) + 1;
       }
     }
-    prevPrevRow = prevRow;
-    prevRow = currRow;
-    currRow = [row + 1];
   }
 
-  return prevRow[len2];
+  return matrix[len1][len2];
 };

EditDistance/src/fuzzyStringMatch.js

@@ -1,41 +1,49 @@
 var fuzzyStringMatch = function(text, query) {
+  if (query === text) {
+    return 0;
+  }
+
+  if (!query.length || !text.length) {
+    return query.length || text.length;
+  }
 
-  var qLen = query.length;
-  var tLen = text.length;
+  var queryLen = query.length;
+  var textLen = text.length;
 
-  var prevPrevRow;
-  var prevRow = [];
-  // Fill in previous row with empty subsequences.
-  for (var col = 0; col <= tLen; col++) {
-    prevRow[col] = 0;
+  // Set up the matrix.
+  var matrix = [];
+  for (var row = 0; row <= queryLen; row++) {
+    var newRow = new Array(textLen + 1);
+    newRow[0] = row;
+    if (row === 0) {
+      for (var col = 1; col <= textLen; col++) {
+        newRow[col] = 0;
+      }
+    }
+    matrix.push(newRow);
   }
-  var currRow = [1];
 
   // Fake iterating through the whole matrix,
   // but remembering only two rows at a time.
-  for (var row = 1; row <= qLen; row++) {
-    for (var col = 1; col <= tLen; col++) {
+  for (var row = 1; row <= queryLen; row++) {
+    for (var col = 1; col <= textLen; col++) {
 
       // If two strings match at their final character, their LCS
       // is the LCS of their prefixes, plus that final character.
       if (query[row-1] === text[col-1]) {
-        currRow[col] = prevRow[col-1];
+        matrix[row][col] = matrix[row-1][col-1];
+
 
       // Otherwise, their LCS is the best LCS that results from
-      // trimming either of their final characters.
+      // trimming either of their final characters, plus one.
       } else {
-        var del = prevRow[col] + 1;
-        var ins = currRow[col-1] + 1;
-        var sub = prevRow[col-1] + 1;
-        currRow[col] = Math.min(del, ins, sub);
-      };
+        var del = matrix[row-1][col] + 1;
+        var ins = matrix[row][col-1] + 1;
+        var sub = matrix[row-1][col-1] + 1;
+        matrix[row][col] = Math.min(del, ins, sub);
+      }
     }
-    prevPrevRow = prevRow;
-    prevRow = currRow;
-    currRow = [row + 1];
   }
-
-  var min = Math.min.apply(null, prevRow);
-  console.log(min, qLen);
-  return (qLen-min)/qLen;
+  var minDistance = Math.min.apply(null, matrix[queryLen]);
+  return 1 - minDistance/queryLen;
 };

Graphics/css/app.css

@@ -0,0 +1,16 @@
+.viewport {
+  position: relative;
+  width: 512px;
+  height: 512px;
+  margin: 50px auto;
+  background-color: #eee;
+  border: 1px solid #ccc;
+}
+
+.point {
+  position: absolute;
+  width:0;
+  height:0;
+  border:2px solid black;
+  border-radius: 2px;
+}

Graphics/index.html

@@ -0,0 +1,16 @@
+<html>
+<head>
+  <title>Graphics!</title>
+  <link rel="stylesheet" href="css/app.css" />  
+  <script src='js/lib/jquery.js'></script>
+  <script src='js/lib/underscore.js'></script>
+  <script src='js/point2D.js'></script>
+  <script src='js/point3D.js'></script>
+  <script src='js/shape.js'></script>
+  <script src='js/init.js'></script>
+</head>
+<body>
+  <div class='viewport'>
+  </div>
+</body>
+</html>

Graphics/js/init.js

@@ -0,0 +1,6 @@
+$(document).ready(function() {
+  var cube = new Cube(new Point3D(0, 0, 0), 100);
+  var rendered = cube.points.map(function(p) {
+    return new Point2D(p.x, p.y);
+  });
+});

Graphics/js/point2D.js

@@ -0,0 +1,21 @@
+var Point2D = function(x, y) {
+  this.move(x, y);
+};
+
+Point2D.prototype.remove = function() {
+  if (this.el) this.el.remove();
+};
+
+Point2D.prototype.render = function() {
+  this.remove();
+  var newEl = $("<div class='point'></div>");
+  newEl.css({top: 256 - this.y, left: this.x + 256});
+  $('.viewport').append(newEl);
+  this.el = newEl;
+};
+
+Point2D.prototype.move = function(x, y) {
+  this.x = x;
+  this.y = y;
+  this.render();
+};

Graphics/js/point3D.js

@@ -0,0 +1,5 @@
+var Point3D = function(x, y, z) {
+  this.x = x;
+  this.y = y;
+  this.z = z;
+};