and example

andrewldesousa · Jun 23, 2024 · a918e18 · a918e18
1 parent 985a88e
commit a918e18
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Showing 2 changed files with 39 additions and 45 deletions.
diff --git a/examples/and.cpp b/examples/and.cpp
@@ -4,65 +4,55 @@
 
 
 int main() {
-    // 4x2 dataset maxtrix shared pointer
-    std::shared_ptr<Scalar<double>> X[4][2];
-    X[0][0] = Scalar<double>::make(0);
-    X[0][1] = Scalar<double>::make(0);
-    X[1][0] = Scalar<double>::make(0);
-    X[1][1] = Scalar<double>::make(1);
-    X[2][0] = Scalar<double>::make(1);
-    X[2][1] = Scalar<double>::make(0);
-    X[3][0] = Scalar<double>::make(1);
-    X[3][1] = Scalar<double>::make(1);
-
-    // labels shared pointer
-    std::shared_ptr<Scalar<double>> Y[4];
-    Y[0] = Scalar<double>::make(0);
-    Y[1] = Scalar<double>::make(0);
-    Y[2] = Scalar<double>::make(0);
-    Y[3] = Scalar<double>::make(1);
-
     // weights shared pointer
     std::shared_ptr<Scalar<double>> w1 = Scalar<double>::make(-.09);
     std::shared_ptr<Scalar<double>> w2 = Scalar<double>::make(.02);
     std::shared_ptr<Scalar<double>> b = Scalar<double>::make(0);
+
     int num_epochs = 10000, num_samples = 4;
-    float learning_rate = 0.001;
+    float learning_rate = 0.0001;
+    auto& graph = ComputationalGraph<double>::get_instance();
 
     for (int i = 0; i < num_epochs; i++) {
-        std::shared_ptr<Scalar<double>> loss = std::make_shared<Scalar<double>>(0);
+        graph.clear();
+
+        std::shared_ptr<Scalar<double>> X[4][2];
+        X[0][0] = Scalar<double>::make(0);
+        X[0][1] = Scalar<double>::make(0);
+        X[1][0] = Scalar<double>::make(0);
+        X[1][1] = Scalar<double>::make(1);
+        X[2][0] = Scalar<double>::make(1);
+        X[2][1] = Scalar<double>::make(0);
+        X[3][0] = Scalar<double>::make(1);
+        X[3][1] = Scalar<double>::make(1);
+
+        // labels shared pointer
+        std::shared_ptr<Scalar<double>> Y[4];
+        Y[0] = Scalar<double>::make(0);
+        Y[1] = Scalar<double>::make(0);
+        Y[2] = Scalar<double>::make(0);
+        Y[3] = Scalar<double>::make(1);
 
+
+        std::shared_ptr<Scalar<double>> loss = std::make_shared<Scalar<double>>(0);
         for (int j = 0; j < num_samples; j++) {
             // forward
-            auto z = w1 * X[j][0];
-            loss = z;
-
-            break;
+            auto z = w1 * X[j][0] + w2 * X[j][1] + b;
+            auto a = sigmoid(z);
+            loss = cross_entropy(Y[j], a) + loss;
         }
 
-        std::cout << "Epoch: " << i << " Loss: " << loss->value << std::endl;
         loss->backward();
-
-        // print updating weights
 
         // update weights
         w1->value = w1->value - learning_rate * w1->grad;
         w2->value = w2->value - learning_rate * w2->grad;
         b->value = b->value - learning_rate * b->grad;
 
-        // print grads
-        // printing
-
-        std::cout << "Printing grads:\n";
-
-        std::cout << "w1 grad: " << w1->grad << std::endl;
-        std::cout << "w2 grad: " << w2->grad << std::endl;
-        std::cout << "b grad: " << b->grad << std::endl;
-
-        // reset gradients
-        w1->grad = 0;
-        w2->grad = 0;
-        b->grad = 0;
+        // print epoch loss
+        if (i % 1000 == 0) {
+            std::cout << "Epoch: " << i << " Loss: " << loss->value << std::endl;
+        }
     }
 
     return 0;

diff --git a/scalar.h b/scalar.h
@@ -28,13 +28,17 @@ class ComputationalGraph {
         return instance;
     }
 
-    void backward() {
-        for (auto node : nodes) { if (node->in_degrees == 0) { node->backward(); } }
-    }
-
     void add_node(std::shared_ptr<Scalar<T>> node) { nodes.insert(node); }
 
-    void clear() { nodes.clear(); }
+    void clear() { 
+        for (auto node : nodes) {
+            node->grad = 0;
+            node->in_degrees = 0;
+            node->children.clear();
+        }
+
+        nodes.clear(); 
+    }
 };