1 files changed, 151 insertions, 0 deletions
diff --git a/rnnlm/rnnlm.js b/rnnlm/rnnlm.js
new file mode 100644
index 0000000..a8d2dc7
--- /dev/null
+++ b/rnnlm/rnnlm.js
@@ -0,0 +1,151 @@
+var $data = [["<bos>", "this", "is", "my", "house", "<eos>"],
+            ["<bos>", "welcome", "to", "my", "house", "<eos>"],
+            ["<bos>", "welcome", "to", "my", "tiny", "house", "<eos>"],
+            ["<bos>", "welcome", "to", "my", "little", "house", "<eos>"]];
+
+var make_vocab = function ($data)
+{
+  var k = 0;
+  var vocab = {}, ivocab = [];
+  for (var i=0; i<$data.length; i++) {
+    for (var j=0; j<$data[i].length; j++) {
+      var w = $data[i][j];
+      if (vocab[w]==undefined) {
+        vocab[w] = k;
+        ivocab[k] = w;
+        k++;
+      }
+    }
+  }
+
+  return [vocab,ivocab,ivocab.length];
+}
+
+var $vocab, $ivocab,$vocab_sz;
+[$vocab,$ivocab,$vocab_sz] = make_vocab($data);
+
+var one_hot = function (n, i)
+{
+  var m = new R.Mat(n,1);
+  m.set(i, 0, 1);
+
+  return m;
+}
+
+var time_step = function (src, tgt, model, lh, solver, hidden_sizes)
+{
+  var G = new R.Graph();
+  var inp = one_hot($vocab_sz, $vocab[src]);
+  var out = R.forwardRNN(G, model, hidden_sizes, inp, lh);
+  var logprobs = out.o;
+  var probs = R.softmax(logprobs);
+  var target = $vocab[tgt];
+  cost = -Math.log(probs.w[target]);
+  logprobs.dw = probs.w;
+  logprobs.dw[target] -= 1;
+  G.backward();
+  solver.step(model, 0.01, 0.0001, 5.0);
+
+  return [model, cost, out, probs];
+}
+
+var stopping_criterion = function (c, d, iter, margin=0.01, max_iter=100)
+{
+  if (Math.abs(c-d) < margin || iter>=max_iter)
+    return true;
+  return false;
+}
+
+var train = function ($data, hidden_sizes)
+{
+  var model = R.initRNN($vocab_sz, hidden_sizes, $vocab_sz);
+  var solver = new R.Solver();
+  lh = {};
+  costs = [];
+  var k = 0;
+  while (true)
+  {
+    var cost = 0.0;
+    for (var i=0; i<$data.length; i++) {
+      for (var j=0; j<$data[i].length-1; j++) {
+        [model, c, lh, probs] = time_step($data[i][j], $data[i][j+1], model, lh, solver, hidden_sizes);
+        cost += c;
+      }
+    }
+    k++;
+    costs.push(cost);
+    if (stopping_criterion(costs[costs.length-2], cost, k))
+      break;
+  }
+
+  return [model, costs];
+}
+
+var generate = function (model, hidden_sizes)
+{
+  var prev = {};
+  var str = "<bos>";
+  var src = "<bos>";
+  while (true) {
+    var G = new R.Graph(false);
+    var inp = one_hot($vocab_sz, $vocab[src]);
+    var lh = R.forwardRNN(G, model, hidden_sizes, inp, prev);
+    prev = lh;
+    var logprobs = lh.o;
+    var probs = R.softmax(logprobs);
+    var x = R.samplei(probs.w);
+    src = $ivocab[x];
+    str += " "+src;
+    if (src == "<eos>")
+      break;
+  }
+
+  return str;
+}
+
+var predict = function (model, hidden_sizes)
+{
+  context = ["<bos>", "welcome", "to", "my"];
+  var prev = {}, lh;
+  var logprobs, probs;
+  for (var i=0; i<context.length; i++) {
+    var G = new R.Graph(false);
+    var inp = one_hot($vocab_sz, $vocab[context[i]]);
+    lh = R.forwardRNN(G, model, hidden_sizes, inp, prev);
+    prev = lh;
+    logprobs = lh.o;
+    probs = R.softmax(logprobs);
+  }
+
+  var maxi = R.maxi(probs.w);
+
+  return [$ivocab[maxi], probs.w[maxi], probs.w];
+}
+
+var main = function ()
+{
+  var hidden_sizes = [20];
+  var [model, costs] = train($data, hidden_sizes);
+
+  for (var i=0; i<costs.length; i++)
+    $("#costs").append('<li>'+costs[i]+'</li>');
+
+  var i=0;
+  while (1) {
+    var s = generate(model, hidden_sizes);
+    $("#samples").append("<li>"+s+"</li>");
+    i++;
+    if (i==13) break;
+  }
+
+  var [t,tp,dist] = predict(model, hidden_sizes);
+  $("#predict").html(t+" ("+tp+")");
+
+  return false;
+}
+
+$(document).ready(function()
+{
+  main();
+});
+